diff --git a/docs/tool-catalog.i18n.yaml b/docs/tool-catalog.i18n.yaml
index 3b76b88253..6391fcaf7f 100644
--- a/docs/tool-catalog.i18n.yaml
+++ b/docs/tool-catalog.i18n.yaml
@@ -243,8 +243,8 @@
   en: 9190a32df5e10ddd
   zh: 48e1b05956d63e26
 /tool-schema-catalog/deepseek-ai-dsh-tool-subagent-control/list-agents:
-  en: 90e684158bcd0b55
-  zh: 23cdd90a05f4909f
+  en: b68f6c31d72980d1
+  zh: 38be7bfea793043c
 /tool-schema-catalog/deepseek-ai-dsh-tool-subagent-control/send-message:
   en: 69c1c0a80c24e3a4
   zh: 8d3e8b8b1137e5c5
diff --git a/docs/tool-catalog.md b/docs/tool-catalog.md
index 811595b41f..18914b13c3 100644
--- a/docs/tool-catalog.md
+++ b/docs/tool-catalog.md
@@ -2147,21 +2147,12 @@ Source: [`packages/subagent/tool-subagent-control/src/index.ts`](../packages/sub
 
 ### `list_agents`
 
-List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.
+List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.
 
 ```json
 {
   "type": "object",
-  "properties": {
-    "scope": {
-      "type": "string",
-      "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-      "enum": [
-        "children",
-        "descendants"
-      ]
-    }
-  }
+  "properties": {}
 }
 ```
 
diff --git a/docs/tool-catalog.zh.md b/docs/tool-catalog.zh.md
index 780df7e476..1c76491da8 100644
--- a/docs/tool-catalog.zh.md
+++ b/docs/tool-catalog.zh.md
@@ -2153,21 +2153,12 @@ lsp 工具将提供方选择和语言服务器子进程置于 ctx.lsp 之后，
 
 ### `list_agents`
 
-列出可联系的代理：你启动的子代理，以及你作为子代理时的父级和可继续同级。每行包含 id、描述和状态。running 表示正在工作，inactive 表示当前未工作。子代理完成时会通知你，无需反复检查；使用 send_message 继续对话。
+列出全部可达的可继续后代；如果调用方是可继续子代理，还列出父代理和可继续同级。行包含 id、描述和状态；后代行还包含父级 id 和深度。可以向父代理、可继续同级和直接子级发送消息，更深后代只接受 interrupt_agent。running 表示正在工作；inactive 表示当前没有工作。直属子代理结束时会收到通知，无需反复查询其状态。使用 send_message 继续对话。
 
 ```json
 {
   "type": "object",
-  "properties": {
-    "scope": {
-      "type": "string",
-      "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-      "enum": [
-        "children",
-        "descendants"
-      ]
-    }
-  }
+  "properties": {}
 }
 ```
 
diff --git a/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.i18n.yaml b/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.i18n.yaml
index de503a5d4e..ca805fd4fa 100644
--- a/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.i18n.yaml
+++ b/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.i18n.yaml
@@ -9,8 +9,8 @@
   en: 32ee389e58de25fe
   zh: 420fd4344f8f1214
 /agent-teams-uses-subagents-and-session-ids/change:
-  en: fb96ccedefaa5eee
-  zh: 7598b8e1f2cffac7
+  en: 208add38ac8dc327
+  zh: c34fce9b2a978e5f
 /agent-teams-uses-subagents-and-session-ids/migration:
   en: 0ed5e22412074192
   zh: 60deae7d46a21c75
diff --git a/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.md b/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.md
index 278d432b62..70d6e7ead2 100644
--- a/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.md
+++ b/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.md
@@ -12,6 +12,7 @@ English | [中文](guide.zh.md)
 The experimental Agent Teams plugins share agent creation, discovery, messaging, and interruption with subagents. Start a teammate with `subagent` or `subagent_fork`, describe its responsibility with `description`, and use its returned agent id for messages and task assignment. Descriptions may repeat and never identify a recipient.
 
 - `spawn_teammate` and the Team-scoped `send_message`, `list_agents`, and `interrupt_agent` are removed. The standard control tools use `agent_id`, not `target`. Continuable children of one live parent can message each other by id.
+- `list_agents` takes no arguments and always lists all reachable continuable descendants, plus a continuable caller’s live parent and siblings. Remove the `scope` argument from scripted calls. Listing deeper descendants does not grant messaging or task-assignment authority.
 - The Team profile no longer disables the subagent tools. Team adds only task tools, `wait_agent`, and collaboration guidance.
 - `agent-team` rejects `maxMembers`, `maxMessageBytes`, and `disposalTimeoutMs`; `tool-agent-team` rejects `interrupt`, `freshProvider`, and `forkProvider`.
 - `ctx.agentTeams` removes `spawnTeammate()`, `sendMessage()`, `interrupt()`, and `listMembers()`. Task views expose `ownerId` instead of `ownerName`; task ownership uses Session ids, including the Lead's id.
diff --git a/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.zh.md b/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.zh.md
index 408763c21d..01ca6ec858 100644
--- a/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.zh.md
+++ b/docs/upgrade-guide/v0.2.1-alpha.3/agent-team-subagents/guide.zh.md
@@ -12,6 +12,7 @@ description: "Agent Teams 使用标准 subagent 工具和 Session id；移除 Te
 实验性 Agent Teams 插件与 subagent 共用代理创建、发现、消息和中断能力。使用 `subagent` 或 `subagent_fork` 创建队友，以 `description` 描述职责，并用返回的 agent id 发送消息和分配任务。描述可以重复，不能作为收件人标识。
 
 - 移除 `spawn_teammate` 以及 Team 作用域的 `send_message`、`list_agents` 和 `interrupt_agent`。标准控制工具使用 `agent_id` 而非 `target`。同一个在线父代理的可继续子代理可以通过 id 互发消息。
+- `list_agents` 不接收参数，始终列出全部可达的可继续后代，以及可继续调用方的在线父级和同级。从脚本调用中移除 `scope` 参数。列出更深后代不会授予消息或任务指派权限。
 - Team profile 不再禁用 subagent 工具。Team 只增加任务工具、`wait_agent` 和协作提示。
 - `agent-team` 拒绝 `maxMembers`、`maxMessageBytes` 和 `disposalTimeoutMs`；`tool-agent-team` 拒绝 `interrupt`、`freshProvider` 和 `forkProvider`。
 - `ctx.agentTeams` 移除 `spawnTeammate()`、`sendMessage()`、`interrupt()` 和 `listMembers()`。任务视图以 `ownerId` 取代 `ownerName`；包括 Lead 在内，任务所有者均使用 Session id。
diff --git a/packages/experimental/tool-agent-team/README.md b/packages/experimental/tool-agent-team/README.md
index 60b1f9aceb..037b7b36dd 100644
--- a/packages/experimental/tool-agent-team/README.md
+++ b/packages/experimental/tool-agent-team/README.md
@@ -128,7 +128,7 @@ The Team Lead and all teammates share the same working directory and filesystem.
 
 Prefer read/edit/write for file changes. If a file operation returns FS_STALE_VERSION, read the current file, rebase your intended change onto the new content, and retry. Bash, formatters, code generators, and scripts are not fully protected by the filesystem version guard; coordinate them explicitly and have the Lead review the final diff and run tests.
 
-Use agent ids as task owners. The Lead can reassign to itself, its direct continuable children, or historical members; other descendants claim tasks themselves. list_agents shows direct contacts by default; descendants scope discovers deeper agents without granting message or assignment authority. inactive means no turn is executing; it does not describe task completion, success, failure, or waiting for other agents. A successful send does not mean the recipient has processed it. Shared-task workflow is list, get, claim with the current revision, perform the work, then complete. Task readiness never starts an owner. Before wait_agent, make sure another required member is running; use send_message first for an inactive direct contact, or coordinate through its parent for a deeper member. wait_agent observes only changes after that call starts, never wakes a member, and returns noProgress immediately when no other member is running. Re-list after wakeup or timeout. The Lead must wait for required teammates before giving the final answer.
+Use agent ids as task owners. The Lead can reassign to itself, its direct continuable children, or historical members; other descendants claim tasks themselves. list_agents shows direct contacts and all reachable continuable descendants; discovery does not grant message or assignment authority. inactive means no turn is executing; it does not describe task completion, success, failure, or waiting for other agents. A successful send does not mean the recipient has processed it. Shared-task workflow is list, get, claim with the current revision, perform the work, then complete. Task readiness never starts an owner. Before wait_agent, make sure another required member is running; use send_message first for an inactive direct contact, or coordinate through its parent for a deeper member. wait_agent observes only changes after that call starts, never wakes a member, and returns noProgress immediately when no other member is running. Re-list after wakeup or timeout. The Lead must wait for required teammates before giving the final answer.
 ```
 
 #### Token effect
diff --git a/packages/experimental/tool-agent-team/README.zh.md b/packages/experimental/tool-agent-team/README.zh.md
index 1554bd9639..d52273921a 100644
--- a/packages/experimental/tool-agent-team/README.zh.md
+++ b/packages/experimental/tool-agent-team/README.zh.md
@@ -128,7 +128,7 @@ The Team Lead and all teammates share the same working directory and filesystem.
 
 Prefer read/edit/write for file changes. If a file operation returns FS_STALE_VERSION, read the current file, rebase your intended change onto the new content, and retry. Bash, formatters, code generators, and scripts are not fully protected by the filesystem version guard; coordinate them explicitly and have the Lead review the final diff and run tests.
 
-Use agent ids as task owners. The Lead can reassign to itself, its direct continuable children, or historical members; other descendants claim tasks themselves. list_agents shows direct contacts by default; descendants scope discovers deeper agents without granting message or assignment authority. inactive means no turn is executing; it does not describe task completion, success, failure, or waiting for other agents. A successful send does not mean the recipient has processed it. Shared-task workflow is list, get, claim with the current revision, perform the work, then complete. Task readiness never starts an owner. Before wait_agent, make sure another required member is running; use send_message first for an inactive direct contact, or coordinate through its parent for a deeper member. wait_agent observes only changes after that call starts, never wakes a member, and returns noProgress immediately when no other member is running. Re-list after wakeup or timeout. The Lead must wait for required teammates before giving the final answer.
+Use agent ids as task owners. The Lead can reassign to itself, its direct continuable children, or historical members; other descendants claim tasks themselves. list_agents shows direct contacts and all reachable continuable descendants; discovery does not grant message or assignment authority. inactive means no turn is executing; it does not describe task completion, success, failure, or waiting for other agents. A successful send does not mean the recipient has processed it. Shared-task workflow is list, get, claim with the current revision, perform the work, then complete. Task readiness never starts an owner. Before wait_agent, make sure another required member is running; use send_message first for an inactive direct contact, or coordinate through its parent for a deeper member. wait_agent observes only changes after that call starts, never wakes a member, and returns noProgress immediately when no other member is running. Re-list after wakeup or timeout. The Lead must wait for required teammates before giving the final answer.
 ```
 
 #### Token 影响
diff --git a/packages/experimental/tool-agent-team/src/index.ts b/packages/experimental/tool-agent-team/src/index.ts
index 74b153e147..cf3b411e21 100644
--- a/packages/experimental/tool-agent-team/src/index.ts
+++ b/packages/experimental/tool-agent-team/src/index.ts
@@ -29,7 +29,7 @@ The Team Lead and all teammates share the same working directory and filesystem.
 
 Prefer read/edit/write for file changes. If a file operation returns FS_STALE_VERSION, read the current file, rebase your intended change onto the new content, and retry. Bash, formatters, code generators, and scripts are not fully protected by the filesystem version guard; coordinate them explicitly and have the Lead review the final diff and run tests.
 
-Use agent ids as task owners. The Lead can reassign to itself, its direct continuable children, or historical members; other descendants claim tasks themselves. list_agents shows direct contacts by default; descendants scope discovers deeper agents without granting message or assignment authority. inactive means no turn is executing; it does not describe task completion, success, failure, or waiting for other agents. A successful send does not mean the recipient has processed it. Shared-task workflow is list, get, claim with the current revision, perform the work, then complete. Task readiness never starts an owner. Before wait_agent, make sure another required member is running; use send_message first for an inactive direct contact, or coordinate through its parent for a deeper member. wait_agent observes only changes after that call starts, never wakes a member, and returns noProgress immediately when no other member is running. Re-list after wakeup or timeout. The Lead must wait for required teammates before giving the final answer.`
+Use agent ids as task owners. The Lead can reassign to itself, its direct continuable children, or historical members; other descendants claim tasks themselves. list_agents shows direct contacts and all reachable continuable descendants; discovery does not grant message or assignment authority. inactive means no turn is executing; it does not describe task completion, success, failure, or waiting for other agents. A successful send does not mean the recipient has processed it. Shared-task workflow is list, get, claim with the current revision, perform the work, then complete. Task readiness never starts an owner. Before wait_agent, make sure another required member is running; use send_message first for an inactive direct contact, or coordinate through its parent for a deeper member. wait_agent observes only changes after that call starts, never wakes a member, and returns noProgress immediately when no other member is running. Re-list after wakeup or timeout. The Lead must wait for required teammates before giving the final answer.`
 
 const NO_ACTIVE_PEER_MESSAGE = 'No other Team member is running. wait_agent cannot make progress or wake inactive teammates. Re-list with list_agents and team_task_list, then use send_message to wake a required inactive direct contact before waiting again; coordinate deeper members through their parent.'
 
diff --git a/packages/subagent/tool-subagent-control/README.i18n.yaml b/packages/subagent/tool-subagent-control/README.i18n.yaml
index 73439c4bc2..c91f1a708e 100644
--- a/packages/subagent/tool-subagent-control/README.i18n.yaml
+++ b/packages/subagent/tool-subagent-control/README.i18n.yaml
@@ -27,8 +27,8 @@
   en: 4ccd504f8886d8b0
   zh: 480ab8cba905ac02
 /deepseek-ai-dsh-tool-subagent-control/use-this-package/list-agents:
-  en: a5cfa30c936ca353
-  zh: d8a83a6190cbd7c8
+  en: 22cd16d544be9f7f
+  zh: 52aa3655d8091ec4
 /deepseek-ai-dsh-tool-subagent-control/understand-the-implementation:
   en: c5cdf01a78c990f2
   zh: 53c180d726ce4502
@@ -39,8 +39,8 @@
   en: b596c53c18b3e7f5
   zh: bd17f4216a3a6301
 /deepseek-ai-dsh-tool-subagent-control/understand-the-implementation/listing-projection:
-  en: 25dd569dbb350eb7
-  zh: bd7ae865d93a6c4b
+  en: 05a40d0cd5acd045
+  zh: 1914d078d4263753
 /deepseek-ai-dsh-tool-subagent-control/understand-the-implementation/source-map:
   en: c86b31cecfd505a0
   zh: 14250cb3bf3e614f
@@ -54,8 +54,8 @@
   en: e4c7376d4f29dbd5
   zh: 6b7a9eaf69c9ea53
 /deepseek-ai-dsh-tool-subagent-control/model-experience/tool-schema/what-the-model-sees:
-  en: d0c7a044fe6b9bf4
-  zh: 94e7b4fc4615f356
+  en: b558efb37bc78acf
+  zh: 8534c438edd306cd
 /deepseek-ai-dsh-tool-subagent-control/model-experience/tool-schema/token-effect:
   en: 282c65ac0eebfbdd
   zh: e9610d49f72918b0
@@ -90,11 +90,11 @@
   en: 094e55d258f2ec2e
   zh: f364bc9046530bff
 /deepseek-ai-dsh-tool-subagent-control/model-experience/listing-result/what-the-model-sees:
-  en: 5d64b578e3301189
-  zh: 68b04cf88e83bde7
+  en: a975a6e493671c84
+  zh: a258b718855972ea
 /deepseek-ai-dsh-tool-subagent-control/model-experience/listing-result/token-effect:
-  en: 55161776c603f199
-  zh: 8e5625243f42dbaa
+  en: d3ced2fbde9382ef
+  zh: 8c7e904ed30f7353
 /deepseek-ai-dsh-tool-subagent-control/model-experience/listing-result/kv-cache-effect:
   en: 4a629edb36a17e32
   zh: 5a7539cfbf404c54
diff --git a/packages/subagent/tool-subagent-control/README.md b/packages/subagent/tool-subagent-control/README.md
index aa835c08af..b1992fc46f 100644
--- a/packages/subagent/tool-subagent-control/README.md
+++ b/packages/subagent/tool-subagent-control/README.md
@@ -53,7 +53,7 @@ Sends a message to the Session id in `agent_id`. Any exact live Agent may target
 
 ### list_agents
 
-Lists agents by id and description. `children` (default) lists direct continuable children from the parent catalog and, for a continuable subagent with a live parent, first lists that parent and its continuable siblings. `descendants` lists only reachable descendants in stable pre-order, with their direct parent id and depth. Live status is `running` or `inactive`. External entries are omitted without reading child Sessions; readable one-shot children are traversal nodes but not output rows. Unknown modes and unreadable child catalogs produce diagnostics only in `descendants` scope. Ordinary Session forks are not catalog entries.
+Lists all reachable continuable descendants in stable pre-order, with each row’s direct parent id and depth. A continuable subagent with a live parent first sees that parent and its continuable siblings. Live status is `running` or `inactive`. External entries are omitted without reading child Sessions; readable one-shot children are traversal nodes but not output rows. Unknown modes and unreadable child catalogs produce diagnostics. Ordinary Session forks are not catalog entries.
 
 -----
 
@@ -75,7 +75,7 @@ The tool forwards its execution signal, which owns admission only until inbox ac
 
 ### Listing projection
 
-`list_agents` reads the caller’s catalog without a cursor and refines status through the live Agent registry. In `children` scope, a continuable caller’s live parent catalog supplies the parent and sibling rows. Descendant traversal preserves catalog order; unknown modes remain traversable with diagnostics, while unreadable catalogs stop that branch. Descendants absent from reachable catalogs cannot be discovered.
+`list_agents` traverses the caller’s catalogs without a cursor and refines status through the live Agent registry. A continuable caller’s live parent catalog supplies the parent and sibling rows. Descendant traversal preserves catalog order; unknown modes remain traversable with diagnostics, while unreadable catalogs stop that branch. Descendants absent from reachable catalogs cannot be discovered.
 
 ### Source map
 
@@ -106,7 +106,7 @@ Read these pages when the package-level contract is not enough; they move from t
 
 #### What the model sees
 
-The generated [schemas](../../../docs/tool-catalog.md#deepseek-aidsh-tool-subagent-control): `send_message` takes an `agent_id` and `message`; `interrupt_agent` takes an `agent_id`; `list_agents` takes an optional `scope`. All addresses are Session ids; descriptions are display text and may repeat.
+The generated [schemas](../../../docs/tool-catalog.md#deepseek-aidsh-tool-subagent-control): `send_message` takes an `agent_id` and `message`; `interrupt_agent` takes an `agent_id`; `list_agents` takes no arguments. All addresses are Session ids; descriptions are display text and may repeat.
 
 #### Token effect
 
@@ -148,11 +148,11 @@ Append-only; newly visible content follows the reusable request prefix and does
 
 #### What the model sees
 
-One line per row in stable order: `<id> [<status>] — <label>`. A continuable child’s `children` list starts with `<id> [<status>] — your parent`, then `<id> [<status>] — sibling: <label>` rows. `descendants` lists neither parent nor siblings and adds ` parent=<id> depth=<n>` before the dash; unknown modes or unreadable catalogs produce `<id> [diagnostic: <reason>]`. Status describes turn activity, not task completion. `(no subagents)` means no row survived the projection.
+One line per descendant in stable order: `<id> [<status>] parent=<id> depth=<n> — <label>`. A continuable child’s list starts with `<id> [<status>] — your parent`, then `<id> [<status>] — sibling: <label>` rows. Unknown modes or unreadable catalogs produce `<id> [diagnostic: <reason>] parent=<id> depth=<n>`. Status describes turn activity, not task completion. `(no subagents)` means no row survived the projection.
 
 #### Token effect
 
-Grows linearly with the listed rows, including parent and siblings in `children` scope. There is no cursor or cap.
+Grows linearly with the listed rows, including parent and siblings. There is no cursor or cap.
 
 #### KV Cache effect
 
diff --git a/packages/subagent/tool-subagent-control/README.zh.md b/packages/subagent/tool-subagent-control/README.zh.md
index 23d73e5526..3f491f4093 100644
--- a/packages/subagent/tool-subagent-control/README.zh.md
+++ b/packages/subagent/tool-subagent-control/README.zh.md
@@ -53,7 +53,7 @@ kind: "package-reference"
 
 ### list_agents
 
-按 id 和描述列出代理。`children`（默认）从父级目录列出直接可继续子级；对于父级在线的可继续子代理，先列父级及可继续同级。`descendants` 只按稳定前序列出可达后代，附带直接父级 id 和深度。在线状态为 `running` 或 `inactive`。外部条目无需读取子 Session 即被省略；可读的一次性子级用于遍历，但不输出行。未知模式和无法读取的子级目录只在 `descendants` 范围产生诊断。普通 Session 分叉不是目录条目。
+按稳定前序列出全部可达的可继续后代，每行带直接父级 id 和深度。父级在线的可继续子代理先看到父级及可继续同级。在线状态为 `running` 或 `inactive`。外部条目无需读取子 Session 即被省略；可读的一次性子级用于遍历，但不输出行。未知模式和无法读取的子级目录产生诊断。普通 Session 分叉不是目录条目。
 
 -----
 
@@ -75,7 +75,7 @@ kind: "package-reference"
 
 ### 列表投影
 
-`list_agents` 无游标读取调用方目录，并通过在线 Agent 注册表细化状态。在 `children` 范围，可继续调用方的在线父级目录提供父级和同级行。后代遍历保留目录顺序；未知模式附带诊断并继续遍历，无法读取的目录则停止该分支。可达目录之外的后代无法被发现。
+`list_agents` 无游标遍历调用方目录，并通过在线 Agent 注册表细化状态。可继续调用方的在线父级目录提供父级和同级行。后代遍历保留目录顺序；未知模式附带诊断并继续遍历，无法读取的目录则停止该分支。可达目录之外的后代无法被发现。
 
 ### 源码地图
 
@@ -106,7 +106,7 @@ kind: "package-reference"
 
 #### 模型看到什么
 
-生成的[模式](../../../docs/tool-catalog.zh.md#deepseek-aidsh-tool-subagent-control)：`send_message` 接收 `agent_id` 和 `message`；`interrupt_agent` 接收 `agent_id`；`list_agents` 接收可选 `scope`。地址统一为 Session id；描述用于展示，可以重复。
+生成的[模式](../../../docs/tool-catalog.zh.md#deepseek-aidsh-tool-subagent-control)：`send_message` 接收 `agent_id` 和 `message`；`interrupt_agent` 接收 `agent_id`；`list_agents` 不接收参数。地址统一为 Session id；描述用于展示，可以重复。
 
 #### Token 影响
 
@@ -148,11 +148,11 @@ kind: "package-reference"
 
 #### 模型看到什么
 
-每行按稳定顺序显示 `<id> [<status>] — <label>`。可继续子级的 `children` 列表先显示 `<id> [<status>] — your parent`，再显示 `<id> [<status>] — sibling: <label>`。`descendants` 不列父级或同级，并在破折号前添加 ` parent=<id> depth=<n>`；未知模式或无法读取的目录输出 `<id> [diagnostic: <reason>]`。状态描述轮次活动，不代表任务完成。`(no subagents)` 表示投影未留下任何行。
+每个后代按稳定顺序显示一行：`<id> [<status>] parent=<id> depth=<n> — <label>`。可继续子级的列表先显示 `<id> [<status>] — your parent`，再显示 `<id> [<status>] — sibling: <label>`。未知模式或无法读取的目录输出 `<id> [diagnostic: <reason>] parent=<id> depth=<n>`。状态描述轮次活动，不代表任务完成。`(no subagents)` 表示投影未留下任何行。
 
 #### Token 影响
 
-随列表行数线性增长，包含 `children` 范围的父级和同级行。没有游标或上限。
+随列表行数线性增长，包含父级和同级行。没有游标或上限。
 
 #### KV Cache 影响
 
diff --git a/packages/subagent/tool-subagent-control/src/list-agents.ts b/packages/subagent/tool-subagent-control/src/list-agents.ts
index 27e851a698..f46fcdfeda 100644
--- a/packages/subagent/tool-subagent-control/src/list-agents.ts
+++ b/packages/subagent/tool-subagent-control/src/list-agents.ts
@@ -1,8 +1,7 @@
 /**
  * The globally named `list_agents` tool: a thin model-facing adapter over
- * the continuable projection of `ctx.subagents.listChildren()` and, for the
- * `descendants` scope, `ctx.subagents.listDescendants()`. A continuable child
- * also sees its live parent and, the other continuable children of that
+ * the continuable projection of `ctx.subagents.listDescendants()`. A continuable
+ * child also sees its live parent and the other continuable children of that
  * parent. It stays separately loadable from the root `send_message` plugin so
  * a deployment can register continuation delivery without exposing discovery.
  * @module @deepseek-ai/dsh-tool-subagent-control/list-agents
@@ -12,24 +11,11 @@ import type { Context } from '@deepseek-ai/cordis'
 import { defineTool } from '@deepseek-ai/dsh-tools'
 import type { Agent } from '@deepseek-ai/dsh-agent'
 import type { SessionId } from '@deepseek-ai/dsh-session'
-import type {
-  SubagentCatalogEntry, SubagentDescendantListEntry, SubagentListEntry,
-} from '@deepseek-ai/dsh-subagent'
-import { assertNever } from '@deepseek-ai/dsh-util-values'
+import type { SubagentDescendantListEntry } from '@deepseek-ai/dsh-subagent'
 
 export const name = 'tool-subagent-list-agents'
 export const inject = ['tools', 'subagents', 'agents']
 
-type ListAgentsScope = 'children' | 'descendants'
-
-interface ListAgentsRequest {
-  readonly scope?: ListAgentsScope
-}
-
-interface ListAgentsSpec {
-  readonly scope: ListAgentsScope
-}
-
 type ListAgentsEntry =
   | {
     readonly kind: 'parent'
@@ -52,11 +38,6 @@ type ListAgentsEntry =
     readonly depth?: number
   }
 
-/** Resolve the optional model request into an internal required-scope spec. */
-function resolveListAgentsRequest(request: ListAgentsRequest): ListAgentsSpec {
-  return { scope: request.scope ?? 'children' }
-}
-
 /** Report turn activity without exposing whether the child is loaded. */
 function statusOf(agents: { get(id: SessionId): Agent | undefined }, id: SessionId): 'running' | 'inactive' {
   return agents.get(id)?.status === 'running' ? 'running' : 'inactive'
@@ -65,11 +46,10 @@ function statusOf(agents: { get(id: SessionId): Agent | undefined }, id: Session
 /** Project one service row into the model-facing entry, or omit a one-shot child. */
 function project(
   agents: { get(id: SessionId): Agent | undefined },
-  entry: SubagentCatalogEntry | SubagentListEntry,
-  position?: Pick<SubagentDescendantListEntry, 'parentId' | 'depth'>,
+  entry: SubagentDescendantListEntry,
 ): ListAgentsEntry | undefined {
-  const at = position === undefined ? {} : { parent: position.parentId, depth: position.depth }
-  if ('kind' in entry && entry.kind === 'diagnostic') {
+  const at = { parent: entry.parentId, depth: entry.depth }
+  if (entry.kind === 'diagnostic') {
     return { kind: 'diagnostic', id: entry.id, reason: entry.reason, ...at }
   }
   // One-shot children cannot be continued by send_message, so the model
@@ -116,19 +96,13 @@ export function apply(ctx: Context): void {
   ctx.tools.register(defineTool({
     name: 'list_agents',
     description:
-      'List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. '
-      + 'Rows carry ids, descriptions, and status. '
+      'List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. '
+      + 'Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. '
+      + 'You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. '
       + 'running means it is working; inactive means it is not currently working. '
-      + 'You will be notified when a subagent finishes; there is no need to keep checking its status. '
+      + 'You will be notified when a direct child finishes; there is no need to keep checking its status. '
       + 'Use send_message to continue the conversation.',
-    parameters: {
-      scope: {
-        type: 'string',
-        enum: ['children', 'descendants'],
-        description: 'children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. '
-          + 'descendants lists the whole tree below you with each entry\'s parent session id and depth; entries deeper than 1 accept only interrupt_agent.',
-      },
-    },
+    parameters: {},
     output: {
       schema: {
         type: 'array',
@@ -169,21 +143,15 @@ export function apply(ctx: Context): void {
           ],
         },
       },
-      render: (args, entries) => {
-        const request = resolveListAgentsRequest(args)
+      render: (_args, entries) => {
         return [{
           type: 'text',
           text: entries.length === 0
             ? '(no subagents)'
             : entries.map((entry) => {
-              // A descendants row always carries its position; children rows
-              // never render it. String() spans the schema-optional shape
-              // without a dead fallback branch.
               if (entry.kind === 'parent') return `${entry.id} [${entry.status}] — your parent`
               if (entry.kind === 'sibling') return `${entry.id} [${entry.status}] — sibling: ${entry.label}`
-              const at = request.scope === 'descendants'
-                ? ` parent=${String(entry.parent)} depth=${String(entry.depth)}`
-                : ''
+              const at = ` parent=${String(entry.parent)} depth=${String(entry.depth)}`
               return entry.kind === 'diagnostic'
                 ? `${entry.id} [diagnostic: ${entry.reason}]${at}`
                 : `${entry.id} [${entry.status}]${at} — ${entry.label}`
@@ -191,34 +159,20 @@ export function apply(ctx: Context): void {
         }]
       },
     },
-    async execute(args, exec) {
+    async execute(_args, exec) {
       const parent = exec.agent
       if (!parent) {
         // Non-agent callers have no session whose children could be listed.
         throw new Error('list_agents requires a calling agent (exec.agent was undefined)')
       }
-      const request = resolveListAgentsRequest(args)
-      switch (request.scope) {
-        case 'children': {
-          const adjacent = await family(ctx, parent, exec.signal)
-          const entries = await ctx.subagents.listChildren(parent.id, exec.signal)
-          return [
-            ...adjacent,
-            ...entries
-              .map(entry => project(ctx.agents, entry))
-              .filter(entry => entry !== undefined),
-          ]
-        }
-        case 'descendants': {
-          const entries = await ctx.subagents.listDescendants(parent.id, exec.signal)
-          return entries
-            .map(entry => project(ctx.agents, entry, entry))
-            .filter(entry => entry !== undefined)
-        }
-        /* v8 ignore next 2 -- the resolver normalizes the schema-validated closed scope before dispatch. */
-        default:
-          return assertNever(request.scope, 'list_agents scope')
-      }
+      const adjacent = await family(ctx, parent, exec.signal)
+      const entries = await ctx.subagents.listDescendants(parent.id, exec.signal)
+      return [
+        ...adjacent,
+        ...entries
+          .map(entry => project(ctx.agents, entry))
+          .filter(entry => entry !== undefined),
+      ]
     },
   }))
 }
diff --git a/packages/subagent/tool-subagent-control/tests/list-agents.spec.ts b/packages/subagent/tool-subagent-control/tests/list-agents.spec.ts
index 900028ca6c..c9d84c3746 100644
--- a/packages/subagent/tool-subagent-control/tests/list-agents.spec.ts
+++ b/packages/subagent/tool-subagent-control/tests/list-agents.spec.ts
@@ -108,7 +108,7 @@ async function waitNoActivation(ctx: Context, childId: SessionId): Promise<void>
 }
 
 describe('dsh-tool-subagent-control/list-agents', () => {
-  it('lists a settled caller-delivery local child in both scopes', async () => {
+  it('lists a settled caller-delivery local child with its tree position', async () => {
     const { ctx, parent } = await setup([textResponse('private result')])
     const started = await ctx.subagents.startActivation({
       delivery: 'caller', provider: 'spawn', label: 'workflow child',
@@ -118,29 +118,23 @@ describe('dsh-tool-subagent-control/list-agents', () => {
     await started.result
     await started.dispose()
 
-    for (const scope of ['children', 'descendants']) {
-      const result = await callTool(ctx, 'list_agents', { scope }, parent)
-      expect(result.isError).toBe(false)
-      expect(text(result)).toBe(scope === 'children'
-        ? `${started.childId} [inactive] — workflow child`
-        : `${started.childId} [inactive] parent=${parent.id} depth=1 — workflow child`)
-    }
+    const result = await callTool(ctx, 'list_agents', {}, parent)
+    expect(result.isError).toBe(false)
+    expect(text(result)).toBe(`${started.childId} [inactive] parent=${parent.id} depth=1 — workflow child`)
   })
 
-  it('omits external leaves from direct and recursive listings without diagnostics', async () => {
+  it('omits external leaves without diagnostics', async () => {
     const { ctx, parent } = await setup([])
     parent.session.append('subagent/catalog', {
       version: 2, childId: SessionId('external-child'), childCreatedAt: 1,
       mode: 'external', label: 'external child',
     })
-    for (const scope of ['children', 'descendants']) {
-      const result = await callTool(ctx, 'list_agents', { scope }, parent)
-      expect(result.isError).toBe(false)
-      expect(text(result)).toBe('(no subagents)')
-    }
+    const result = await callTool(ctx, 'list_agents', {}, parent)
+    expect(result.isError).toBe(false)
+    expect(text(result)).toBe('(no subagents)')
   })
 
-  it('registers list_agents once, globally, with only the optional scope parameter', async () => {
+  it('registers list_agents once, globally, without parameters', async () => {
     const { ctx } = await setup([])
     const schemas = ctx.tools.schemas().filter(schema => schema.name === 'list_agents')
     expect(schemas).toHaveLength(1)
@@ -148,11 +142,10 @@ describe('dsh-tool-subagent-control/list-agents', () => {
       properties?: Record<string, { enum?: string[]; description?: string }>
       required?: string[]
     }
-    expect(Object.keys(parameters.properties ?? {})).toEqual(['scope'])
-    expect(parameters.properties?.scope?.enum).toEqual(['children', 'descendants'])
+    expect(Object.keys(parameters.properties ?? {})).toEqual([])
     expect(parameters.required ?? []).toEqual([])
-    expect(parameters.properties?.scope?.description).toContain('accepts send_message in any status')
-    expect(parameters.properties?.scope?.description).toContain('accept only interrupt_agent')
+    expect(schemas[0]?.description).toContain('You can message your parent, continuable siblings, and direct children')
+    expect(schemas[0]?.description).toContain('Deeper descendants accept only interrupt_agent')
   })
 
   it('renders the empty result as (no subagents)', async () => {
@@ -175,7 +168,7 @@ describe('dsh-tool-subagent-control/list-agents', () => {
     // Pin the render deterministically past the service: the tool is a thin
     // adapter, so its fixed text forms are what this test pins. Status comes
     // from the live Agent registry, stubbed per candidate id.
-    const entries: SubagentCatalogEntry[] = [
+    const entries = [
       {
         id: SessionId('one-shot-child'),
         createdAt: 1,
@@ -200,8 +193,11 @@ describe('dsh-tool-subagent-control/list-agents', () => {
         label: 'waiting on descendants',
         mode: 'continuable',
       },
-    ]
-    ctx.subagents.listChildren = () => Promise.resolve(entries)
+    ] satisfies SubagentCatalogEntry[]
+    ctx.subagents.listDescendants = () => Promise.resolve(entries.map(entry => ({
+      ...entry, kind: 'child' as const, activity: 'inactive' as const, hasChildren: false,
+      parentId: parent.id, depth: 1,
+    })))
     const agents = new Map<string, {
       status: 'running' | 'idle'
     }>([
@@ -212,24 +208,24 @@ describe('dsh-tool-subagent-control/list-agents', () => {
     const result = await callTool(ctx, 'list_agents', {}, parent)
     expect(result.isError).toBe(false)
     expect(text(result)).toBe(
-      `${started.childId} [inactive] — real child\n`
-      + 'running-child [running] — still working\n'
-      + 'waiting-child [inactive] — waiting on descendants',
+      `${started.childId} [inactive] parent=${parent.id} depth=1 — real child\n`
+      + `running-child [running] parent=${parent.id} depth=1 — still working\n`
+      + `waiting-child [inactive] parent=${parent.id} depth=1 — waiting on descendants`,
     )
   })
 
-  it('resolves omitted scope to children and passes the parent id and cancellation signal', async () => {
+  it('always lists descendants and forwards the caller id and cancellation signal', async () => {
     const { ctx, parent } = await setup([])
     const signal = new AbortController().signal
-    const listChildren = vi.spyOn(ctx.subagents, 'listChildren').mockResolvedValue([])
+    const listDescendants = vi.spyOn(ctx.subagents, 'listDescendants').mockResolvedValue([])
 
     const result = await callTool(ctx, 'list_agents', {}, parent, signal)
 
     expect(result.isError).toBe(false)
-    expect(listChildren).toHaveBeenCalledWith(parent.id, signal)
+    expect(listDescendants).toHaveBeenCalledWith(parent.id, signal)
   })
 
-  it('lists a real settled continuable child and omits a historical one-shot sibling', async () => {
+  it('reports an unreadable historical branch alongside a settled continuable child', async () => {
     const { ctx, parent } = await setup([textResponse('done')])
     parent.session.append('subagent/catalog', {
       version: 1, childId: SessionId('historical-one-shot'), childCreatedAt: 1,
@@ -244,7 +240,10 @@ describe('dsh-tool-subagent-control/list-agents', () => {
     await waitNoActivation(ctx, started.childId)
     const result = await callTool(ctx, 'list_agents', {}, parent)
     expect(result.isError).toBe(false)
-    expect(text(result)).toBe(`${started.childId} [inactive] — summarize the doc`)
+    expect(text(result)).toBe(
+      `historical-one-shot [diagnostic: unavailable] parent=${parent.id} depth=1\n`
+      + `${started.childId} [inactive] parent=${parent.id} depth=1 — summarize the doc`,
+    )
   })
 
   it('describes inactive as turn availability and pins the status vocabulary', async () => {
@@ -252,7 +251,7 @@ describe('dsh-tool-subagent-control/list-agents', () => {
     const schema = ctx.tools.schemas().find(candidate => candidate.name === 'list_agents')
     // Completion reaches the parent through its notice; listing is discovery,
     // so its inactive status must not send the model looking for a result.
-    expect(schema?.description).toContain('You will be notified when a subagent finishes')
+    expect(schema?.description).toContain('You will be notified when a direct child finishes')
     expect(schema?.description).toContain('inactive means it is not currently working')
     // The enum is the closed vocabulary the model renders, so pin it rather than
     // scanning prose that legitimately reads "not to poll for completion".
@@ -318,7 +317,7 @@ describe('dsh-tool-subagent-control/list-agents', () => {
       expect(ctx.agents.get(started.childId)?.status).toBe('idle')
     }, { timeout: 5_000 })
 
-    const result = await callTool(ctx, 'list_agents', { scope: 'descendants' }, parent)
+    const result = await callTool(ctx, 'list_agents', {}, parent)
     expect(result.isError).toBe(false)
     expect(text(result)).toBe(
       `${started.childId} [inactive] parent=${parent.id} depth=1 — waiting branch\n`
@@ -363,7 +362,7 @@ describe('dsh-tool-subagent-control/list-agents', () => {
         depth: 1,
       },
     ])
-    const result = await callTool(ctx, 'list_agents', { scope: 'descendants' }, parent)
+    const result = await callTool(ctx, 'list_agents', {}, parent)
     expect(result.isError).toBe(false)
     expect(text(result)).toBe(
       'deep-leaf [inactive] parent=one-shot-mid depth=2 — deep leaf\n'
@@ -371,17 +370,6 @@ describe('dsh-tool-subagent-control/list-agents', () => {
     )
   })
 
-  it('preserves explicit descendants scope and forwards the tool cancellation signal', async () => {
-    const { ctx, parent } = await setup([])
-    const signal = new AbortController().signal
-    const listDescendants = vi.spyOn(ctx.subagents, 'listDescendants').mockResolvedValue([])
-
-    const result = await callTool(ctx, 'list_agents', { scope: 'descendants' }, parent, signal)
-
-    expect(result.isError).toBe(false)
-    expect(listDescendants).toHaveBeenCalledWith(parent.id, signal)
-  })
-
   it('shows each continuable child its parent and siblings by id with their descriptions', async () => {
     const release = Promise.withResolvers<undefined>()
     const releaseDelta = Promise.withResolvers<undefined>()
@@ -422,10 +410,10 @@ describe('dsh-tool-subagent-control/list-agents', () => {
     ].join('\n'))
     const fromParent = await callTool(ctx, 'list_agents', {}, parent)
     expect(text(fromParent)).toBe([
-      `${alpha} [running] — alpha task`,
-      `${beta} [inactive] — beta task`,
-      `${gamma} [inactive] — gamma task`,
-      `${delta} [running] — delta task`,
+      `${alpha} [running] parent=${parent.id} depth=1 — alpha task`,
+      `${beta} [inactive] parent=${parent.id} depth=1 — beta task`,
+      `${gamma} [inactive] parent=${parent.id} depth=1 — gamma task`,
+      `${delta} [running] parent=${parent.id} depth=1 — delta task`,
     ].join('\n'))
 
     const catalog = vi.spyOn(ctx.subagents, 'listChildren').mockResolvedValue([])
diff --git a/snapshots/sdk/bash-tool/tool-schemas.expected.json b/snapshots/sdk/bash-tool/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/sdk/bash-tool/tool-schemas.expected.json
+++ b/snapshots/sdk/bash-tool/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/sdk/subagent-activation-limit/tool-schemas.1.expected.json b/snapshots/sdk/subagent-activation-limit/tool-schemas.1.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/sdk/subagent-activation-limit/tool-schemas.1.expected.json
+++ b/snapshots/sdk/subagent-activation-limit/tool-schemas.1.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/sdk/subagent-continuable-inheritance/tool-schemas.1.expected.json b/snapshots/sdk/subagent-continuable-inheritance/tool-schemas.1.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/sdk/subagent-continuable-inheritance/tool-schemas.1.expected.json
+++ b/snapshots/sdk/subagent-continuable-inheritance/tool-schemas.1.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/sdk/subagent-continuable/tool-schemas.1.expected.json b/snapshots/sdk/subagent-continuable/tool-schemas.1.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/sdk/subagent-continuable/tool-schemas.1.expected.json
+++ b/snapshots/sdk/subagent-continuable/tool-schemas.1.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/sdk/subagent-dsh-sdk-diagnostic/tool-schemas.expected.json b/snapshots/sdk/subagent-dsh-sdk-diagnostic/tool-schemas.expected.json
index 17afbf5acf..31b1dbfb2b 100644
--- a/snapshots/sdk/subagent-dsh-sdk-diagnostic/tool-schemas.expected.json
+++ b/snapshots/sdk/subagent-dsh-sdk-diagnostic/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/sdk/subagent-dsh-sdk-dynamic-route/tool-schemas.1.expected.json b/snapshots/sdk/subagent-dsh-sdk-dynamic-route/tool-schemas.1.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/sdk/subagent-dsh-sdk-dynamic-route/tool-schemas.1.expected.json
+++ b/snapshots/sdk/subagent-dsh-sdk-dynamic-route/tool-schemas.1.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/sdk/subagent-dsh-sdk-dynamic-route/tool-schemas.expected.json b/snapshots/sdk/subagent-dsh-sdk-dynamic-route/tool-schemas.expected.json
index e7da2ccf6c..d09f364adc 100644
--- a/snapshots/sdk/subagent-dsh-sdk-dynamic-route/tool-schemas.expected.json
+++ b/snapshots/sdk/subagent-dsh-sdk-dynamic-route/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/sdk/subagent-list-agents/session.v4.jsonl b/snapshots/sdk/subagent-list-agents/session.v4.jsonl
index 94a0363181..fad282a574 100644
--- a/snapshots/sdk/subagent-list-agents/session.v4.jsonl
+++ b/snapshots/sdk/subagent-list-agents/session.v4.jsonl
@@ -34,8 +34,8 @@
 {"type":"agent/inbox/spliced","data":{"target":"next-turn","start":0,"removedCount":1,"inserted":[]}}
 {"type":"step/start","data":{"turn":3,"step":1}}
 {"type":"user/message","data":{"content":[{"type":"text","text":"Call list_agents once and observe the subagent you started. Then call interrupt_agent once with agent_id set to {{session:2}}. Then reply with the single word DONE. Do not call any other tool."}],"source":{"kind":"user"},"role":"user","id":"{{message:9}}"},"surfaceOp":"append"}
-{"type":"assistant/message","data":{"turn":3,"step":1,"message":{"role":"assistant","content":[{"type":"tool-call","id":"call_list","name":"list_agents","arguments":"{\"scope\":\"descendants\"}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"{{message:10}}"},"usage":{"inputTokens":10,"outputTokens":5},"stream":[{"type":"chunk","time":1788880389662,"chunk":{"type":"block-start","index":0,"blockType":"tool-call"}},{"type":"tool-call-chunks","time0":1788880389662,"index":0,"dt":[],"id":"call_list","name":"list_agents","args":["{\"scope\":\"descendants\"}"]},{"type":"chunk","time":1788880389662,"chunk":{"type":"block-end","index":0,"block":{"type":"tool-call","id":"call_list","name":"list_agents","arguments":"{\"scope\":\"descendants\"}"}}},{"type":"chunk","time":1788880389662,"chunk":{"type":"usage","usage":{"inputTokens":10,"outputTokens":5}}},{"type":"chunk","time":1788880389662,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}]},"surfaceOp":"append"}
-{"type":"tool/call","data":{"turn":3,"step":1,"callId":"call_list","name":"list_agents","arguments":"{\"scope\":\"descendants\"}"}}
+{"type":"assistant/message","data":{"turn":3,"step":1,"message":{"role":"assistant","content":[{"type":"tool-call","id":"call_list","name":"list_agents","arguments":"{}"}],"source":{"kind":"model","provider":"deepseek-official","model":"deepseek-v4-flash"},"id":"{{message:10}}"},"usage":{"inputTokens":10,"outputTokens":5},"stream":[{"type":"chunk","time":1788880389662,"chunk":{"type":"block-start","index":0,"blockType":"tool-call"}},{"type":"tool-call-chunks","time0":1788880389662,"index":0,"dt":[],"id":"call_list","name":"list_agents","args":["{}"]},{"type":"chunk","time":1788880389662,"chunk":{"type":"block-end","index":0,"block":{"type":"tool-call","id":"call_list","name":"list_agents","arguments":"{}"}}},{"type":"chunk","time":1788880389662,"chunk":{"type":"usage","usage":{"inputTokens":10,"outputTokens":5}}},{"type":"chunk","time":1788880389662,"chunk":{"type":"finish","reason":{"kind":"tool-calls"}}}]},"surfaceOp":"append"}
+{"type":"tool/call","data":{"turn":3,"step":1,"callId":"call_list","name":"list_agents","arguments":"{}"}}
 {"type":"tool/result","data":{"turn":3,"step":1,"message":{"role":"tool","source":{"kind":"tool","callId":"call_list"},"toolCallId":"call_list","content":[{"type":"text","text":"{{session:2}} [inactive] parent={{session:1}} depth=1 — Reply with CHILD_OK"}],"isError":false,"id":"{{message:11}}"}},"sourceEventSeqs":[36],"surfaceOp":"append"}
 {"type":"step/end","data":{"turn":3,"step":1}}
 {"type":"step/start","data":{"turn":3,"step":2}}
diff --git a/snapshots/sdk/subagent-list-agents/tool-schemas.1.expected.json b/snapshots/sdk/subagent-list-agents/tool-schemas.1.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/sdk/subagent-list-agents/tool-schemas.1.expected.json
+++ b/snapshots/sdk/subagent-list-agents/tool-schemas.1.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/sdk/subagent-send-message/tool-schemas.1.expected.json b/snapshots/sdk/subagent-send-message/tool-schemas.1.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/sdk/subagent-send-message/tool-schemas.1.expected.json
+++ b/snapshots/sdk/subagent-send-message/tool-schemas.1.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/sdk/text-turn/tool-schemas.expected.json b/snapshots/sdk/text-turn/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/sdk/text-turn/tool-schemas.expected.json
+++ b/snapshots/sdk/text-turn/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/sdk/tool-error-details/system-prompt.expected.md b/snapshots/sdk/tool-error-details/system-prompt.expected.md
index 85ea6c1e0e..fd8dc5b49a 100644
--- a/snapshots/sdk/tool-error-details/system-prompt.expected.md
+++ b/snapshots/sdk/tool-error-details/system-prompt.expected.md
@@ -168,11 +168,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/sdk/tool-error-details/tool-schemas.expected.json b/snapshots/sdk/tool-error-details/tool-schemas.expected.json
index f84accc115..5c039e7d30 100644
--- a/snapshots/sdk/tool-error-details/tool-schemas.expected.json
+++ b/snapshots/sdk/tool-error-details/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/advanced-toolchain/system-prompt.expected.md b/snapshots/session/advanced-toolchain/system-prompt.expected.md
index fadb4af746..5b2ad2c326 100644
--- a/snapshots/session/advanced-toolchain/system-prompt.expected.md
+++ b/snapshots/session/advanced-toolchain/system-prompt.expected.md
@@ -181,11 +181,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/session/advanced-toolchain/tool-schemas.expected.json b/snapshots/session/advanced-toolchain/tool-schemas.expected.json
index 117179fb58..8f95aafff2 100644
--- a/snapshots/session/advanced-toolchain/tool-schemas.expected.json
+++ b/snapshots/session/advanced-toolchain/tool-schemas.expected.json
@@ -286,19 +286,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
@@ -999,19 +990,10 @@
       },
       {
         "name": "list_agents",
-        "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+        "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
         "parameters": {
           "type": "object",
-          "properties": {
-            "scope": {
-              "type": "string",
-              "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-              "enum": [
-                "children",
-                "descendants"
-              ]
-            }
-          }
+          "properties": {}
         }
       },
       {
diff --git a/snapshots/session/agent-instructions/tool-schemas.expected.json b/snapshots/session/agent-instructions/tool-schemas.expected.json
index 9cd29d23df..e08573c1ef 100644
--- a/snapshots/session/agent-instructions/tool-schemas.expected.json
+++ b/snapshots/session/agent-instructions/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
@@ -878,19 +869,10 @@
       },
       {
         "name": "list_agents",
-        "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+        "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
         "parameters": {
           "type": "object",
-          "properties": {
-            "scope": {
-              "type": "string",
-              "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-              "enum": [
-                "children",
-                "descendants"
-              ]
-            }
-          }
+          "properties": {}
         }
       },
       {
diff --git a/snapshots/session/background-confinement-failure/tool-schemas.expected.json b/snapshots/session/background-confinement-failure/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/session/background-confinement-failure/tool-schemas.expected.json
+++ b/snapshots/session/background-confinement-failure/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/both-mode-turn/system-prompt.expected.md b/snapshots/session/both-mode-turn/system-prompt.expected.md
index 35514c1905..b6cc6f95b1 100644
--- a/snapshots/session/both-mode-turn/system-prompt.expected.md
+++ b/snapshots/session/both-mode-turn/system-prompt.expected.md
@@ -135,11 +135,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/session/browser-use-chrome-devtools-mcp/tool-schemas.expected.json b/snapshots/session/browser-use-chrome-devtools-mcp/tool-schemas.expected.json
index 474bfffdd9..5cae3dc33a 100644
--- a/snapshots/session/browser-use-chrome-devtools-mcp/tool-schemas.expected.json
+++ b/snapshots/session/browser-use-chrome-devtools-mcp/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/browser-use-playwright-mcp/tool-schemas.expected.json b/snapshots/session/browser-use-playwright-mcp/tool-schemas.expected.json
index 7da4dad78c..847dfbd5e4 100644
--- a/snapshots/session/browser-use-playwright-mcp/tool-schemas.expected.json
+++ b/snapshots/session/browser-use-playwright-mcp/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/browser-use-stagehand-native/tool-schemas.expected.json b/snapshots/session/browser-use-stagehand-native/tool-schemas.expected.json
index 4923eea64c..0a0285ca47 100644
--- a/snapshots/session/browser-use-stagehand-native/tool-schemas.expected.json
+++ b/snapshots/session/browser-use-stagehand-native/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/claude-code-mods/tool-schemas.expected.json b/snapshots/session/claude-code-mods/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/session/claude-code-mods/tool-schemas.expected.json
+++ b/snapshots/session/claude-code-mods/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/compaction-recovery/tool-schemas.expected.json b/snapshots/session/compaction-recovery/tool-schemas.expected.json
index 9cd29d23df..e08573c1ef 100644
--- a/snapshots/session/compaction-recovery/tool-schemas.expected.json
+++ b/snapshots/session/compaction-recovery/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
@@ -878,19 +869,10 @@
       },
       {
         "name": "list_agents",
-        "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+        "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
         "parameters": {
           "type": "object",
-          "properties": {
-            "scope": {
-              "type": "string",
-              "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-              "enum": [
-                "children",
-                "descendants"
-              ]
-            }
-          }
+          "properties": {}
         }
       },
       {
diff --git a/snapshots/session/computer-use-cua-driver-mcp/tool-schemas.expected.json b/snapshots/session/computer-use-cua-driver-mcp/tool-schemas.expected.json
index 5c42099de3..2d60121149 100644
--- a/snapshots/session/computer-use-cua-driver-mcp/tool-schemas.expected.json
+++ b/snapshots/session/computer-use-cua-driver-mcp/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/computer-use-cua-driver-native/tool-schemas.expected.json b/snapshots/session/computer-use-cua-driver-native/tool-schemas.expected.json
index e9c1ed3e77..ae92347dfa 100644
--- a/snapshots/session/computer-use-cua-driver-native/tool-schemas.expected.json
+++ b/snapshots/session/computer-use-cua-driver-native/tool-schemas.expected.json
@@ -291,19 +291,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/cordis-inspect-jsdoc/tool-schemas.expected.json b/snapshots/session/cordis-inspect-jsdoc/tool-schemas.expected.json
index 747790aa01..79c1ac3351 100644
--- a/snapshots/session/cordis-inspect-jsdoc/tool-schemas.expected.json
+++ b/snapshots/session/cordis-inspect-jsdoc/tool-schemas.expected.json
@@ -286,19 +286,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/cua-native/tool-schemas.expected.json b/snapshots/session/cua-native/tool-schemas.expected.json
index ca35b42120..42971bf07a 100644
--- a/snapshots/session/cua-native/tool-schemas.expected.json
+++ b/snapshots/session/cua-native/tool-schemas.expected.json
@@ -1384,19 +1384,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/cua-ptc/system-prompt.expected.md b/snapshots/session/cua-ptc/system-prompt.expected.md
index 91489b698f..de34254453 100644
--- a/snapshots/session/cua-ptc/system-prompt.expected.md
+++ b/snapshots/session/cua-ptc/system-prompt.expected.md
@@ -180,11 +180,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/session/deepseek-messages-system-prompt/tool-schemas.expected.json b/snapshots/session/deepseek-messages-system-prompt/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/session/deepseek-messages-system-prompt/tool-schemas.expected.json
+++ b/snapshots/session/deepseek-messages-system-prompt/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/deepseek-protocol-system-prompt/tool-schemas.expected.json b/snapshots/session/deepseek-protocol-system-prompt/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/session/deepseek-protocol-system-prompt/tool-schemas.expected.json
+++ b/snapshots/session/deepseek-protocol-system-prompt/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/dynamic-tool-updates/tool-schemas.expected.json b/snapshots/session/dynamic-tool-updates/tool-schemas.expected.json
index 9a06d85fea..99cb26ac26 100644
--- a/snapshots/session/dynamic-tool-updates/tool-schemas.expected.json
+++ b/snapshots/session/dynamic-tool-updates/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
@@ -878,19 +869,10 @@
       },
       {
         "name": "list_agents",
-        "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+        "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
         "parameters": {
           "type": "object",
-          "properties": {
-            "scope": {
-              "type": "string",
-              "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-              "enum": [
-                "children",
-                "descendants"
-              ]
-            }
-          }
+          "properties": {}
         }
       },
       {
@@ -1518,19 +1500,10 @@
       },
       {
         "name": "list_agents",
-        "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+        "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
         "parameters": {
           "type": "object",
-          "properties": {
-            "scope": {
-              "type": "string",
-              "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-              "enum": [
-                "children",
-                "descendants"
-              ]
-            }
-          }
+          "properties": {}
         }
       },
       {
diff --git a/snapshots/session/foreground-confinement-timeout/tool-schemas.expected.json b/snapshots/session/foreground-confinement-timeout/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/session/foreground-confinement-timeout/tool-schemas.expected.json
+++ b/snapshots/session/foreground-confinement-timeout/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/fs-glob-sampling/tool-schemas.expected.json b/snapshots/session/fs-glob-sampling/tool-schemas.expected.json
index 1fde39dce8..5a272e965a 100644
--- a/snapshots/session/fs-glob-sampling/tool-schemas.expected.json
+++ b/snapshots/session/fs-glob-sampling/tool-schemas.expected.json
@@ -165,19 +165,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/lsp-definition/tool-schemas.expected.json b/snapshots/session/lsp-definition/tool-schemas.expected.json
index d8886128a8..4b13981451 100644
--- a/snapshots/session/lsp-definition/tool-schemas.expected.json
+++ b/snapshots/session/lsp-definition/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/mcp-resources-ptc/system-prompt.expected.md b/snapshots/session/mcp-resources-ptc/system-prompt.expected.md
index 510bf38383..fff9e5fe63 100644
--- a/snapshots/session/mcp-resources-ptc/system-prompt.expected.md
+++ b/snapshots/session/mcp-resources-ptc/system-prompt.expected.md
@@ -143,11 +143,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** List parameterized resource URI templates from an MCP server. */
   list_mcp_resource_templates: {
     /** Configured MCP server name. */
diff --git a/snapshots/session/mcp-resources/tool-schemas.expected.json b/snapshots/session/mcp-resources/tool-schemas.expected.json
index e406d50839..8fe57329b1 100644
--- a/snapshots/session/mcp-resources/tool-schemas.expected.json
+++ b/snapshots/session/mcp-resources/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/multimodal-spill-ends/tool-schemas.expected.json b/snapshots/session/multimodal-spill-ends/tool-schemas.expected.json
index 1a59236e3c..8643290037 100644
--- a/snapshots/session/multimodal-spill-ends/tool-schemas.expected.json
+++ b/snapshots/session/multimodal-spill-ends/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/office-progressive-native/tool-schemas.expected.json b/snapshots/session/office-progressive-native/tool-schemas.expected.json
index 1e0754adc3..f0e844ff6d 100644
--- a/snapshots/session/office-progressive-native/tool-schemas.expected.json
+++ b/snapshots/session/office-progressive-native/tool-schemas.expected.json
@@ -200,19 +200,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/office-progressive-ptc/system-prompt.expected.md b/snapshots/session/office-progressive-ptc/system-prompt.expected.md
index 2060ba9add..7e945a9b48 100644
--- a/snapshots/session/office-progressive-ptc/system-prompt.expected.md
+++ b/snapshots/session/office-progressive-ptc/system-prompt.expected.md
@@ -114,11 +114,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/session/office-skills/tool-schemas.expected.json b/snapshots/session/office-skills/tool-schemas.expected.json
index 1e0754adc3..f0e844ff6d 100644
--- a/snapshots/session/office-skills/tool-schemas.expected.json
+++ b/snapshots/session/office-skills/tool-schemas.expected.json
@@ -200,19 +200,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/persistent-pwsh-tool-turn/tool-schemas.expected.json b/snapshots/session/persistent-pwsh-tool-turn/tool-schemas.expected.json
index 715774b3bf..5e76c9627d 100644
--- a/snapshots/session/persistent-pwsh-tool-turn/tool-schemas.expected.json
+++ b/snapshots/session/persistent-pwsh-tool-turn/tool-schemas.expected.json
@@ -120,19 +120,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/plugin-manager-mcp/tool-schemas.expected.json b/snapshots/session/plugin-manager-mcp/tool-schemas.expected.json
index 1382dcd8d4..a5770e6380 100644
--- a/snapshots/session/plugin-manager-mcp/tool-schemas.expected.json
+++ b/snapshots/session/plugin-manager-mcp/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
@@ -939,19 +930,10 @@
       },
       {
         "name": "list_agents",
-        "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+        "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
         "parameters": {
           "type": "object",
-          "properties": {
-            "scope": {
-              "type": "string",
-              "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-              "enum": [
-                "children",
-                "descendants"
-              ]
-            }
-          }
+          "properties": {}
         }
       },
       {
diff --git a/snapshots/session/plugin-manager/tool-schemas.expected.json b/snapshots/session/plugin-manager/tool-schemas.expected.json
index 9940c1c286..aac330649c 100644
--- a/snapshots/session/plugin-manager/tool-schemas.expected.json
+++ b/snapshots/session/plugin-manager/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/product-subagent-both/tool-schemas.expected.json b/snapshots/session/product-subagent-both/tool-schemas.expected.json
index b2662863a5..e9778f1492 100644
--- a/snapshots/session/product-subagent-both/tool-schemas.expected.json
+++ b/snapshots/session/product-subagent-both/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/product-subagent-codex/tool-schemas.expected.json b/snapshots/session/product-subagent-codex/tool-schemas.expected.json
index fb017887d9..bf02723253 100644
--- a/snapshots/session/product-subagent-codex/tool-schemas.expected.json
+++ b/snapshots/session/product-subagent-codex/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/product-subagent-result-diagnostic/tool-schemas.expected.json b/snapshots/session/product-subagent-result-diagnostic/tool-schemas.expected.json
index 51521633e0..87df175ba4 100644
--- a/snapshots/session/product-subagent-result-diagnostic/tool-schemas.expected.json
+++ b/snapshots/session/product-subagent-result-diagnostic/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/provider-cwd/tool-schemas.expected.json b/snapshots/session/provider-cwd/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/session/provider-cwd/tool-schemas.expected.json
+++ b/snapshots/session/provider-cwd/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/ptc-node-read-only/system-prompt.expected.md b/snapshots/session/ptc-node-read-only/system-prompt.expected.md
index 3854aa2dca..80c671f372 100644
--- a/snapshots/session/ptc-node-read-only/system-prompt.expected.md
+++ b/snapshots/session/ptc-node-read-only/system-prompt.expected.md
@@ -135,11 +135,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/session/ptc-node-workspace/system-prompt.expected.md b/snapshots/session/ptc-node-workspace/system-prompt.expected.md
index 3854aa2dca..80c671f372 100644
--- a/snapshots/session/ptc-node-workspace/system-prompt.expected.md
+++ b/snapshots/session/ptc-node-workspace/system-prompt.expected.md
@@ -135,11 +135,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/session/ptc-persistent/system-prompt.expected.md b/snapshots/session/ptc-persistent/system-prompt.expected.md
index 3854aa2dca..80c671f372 100644
--- a/snapshots/session/ptc-persistent/system-prompt.expected.md
+++ b/snapshots/session/ptc-persistent/system-prompt.expected.md
@@ -135,11 +135,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/session/ptc-policy-change/system-prompt.expected.md b/snapshots/session/ptc-policy-change/system-prompt.expected.md
index 1b9cd382a4..e2ae9d653d 100644
--- a/snapshots/session/ptc-policy-change/system-prompt.expected.md
+++ b/snapshots/session/ptc-policy-change/system-prompt.expected.md
@@ -135,11 +135,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/session/ptc-python-turn/system-prompt.expected.md b/snapshots/session/ptc-python-turn/system-prompt.expected.md
index 8d6322ca26..586a413269 100644
--- a/snapshots/session/ptc-python-turn/system-prompt.expected.md
+++ b/snapshots/session/ptc-python-turn/system-prompt.expected.md
@@ -267,11 +267,6 @@ class JobOutputOutput(TypedDict):
     text: str
     job: JobOutputOutputJob
 
-class ListAgentsArgs(TypedDict):
-    # children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.
-    scope: NotRequired[Literal["children", "descendants"]]
-    # Additional keys beyond those declared are allowed.
-
 class ListAgentsOutput1(TypedDict):
     kind: Literal["parent"]
     id: str
@@ -538,8 +533,8 @@ class Tools(Protocol):
         """List your background jobs (running and finished) with their ids, kinds, and statuses."""
     async def job_output(self, args: JobOutputArgs) -> JobOutputOutput:
         """Read a background job: output since the previous read for stream jobs, or the result of a finished final-output job."""
-    async def list_agents(self, args: ListAgentsArgs) -> list[ListAgentsOutput1 | ListAgentsOutput2 | ListAgentsOutput3]:
-        """List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation."""
+    async def list_agents(self, args: dict[str, Any]) -> list[ListAgentsOutput1 | ListAgentsOutput2 | ListAgentsOutput3]:
+        """List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation."""
     async def read(self, args: ReadArgs) -> ReadOutput:
         """Read a UTF-8 text file and return line-numbered content."""
     async def read_image(self, args: ReadImageArgs) -> ReadImageOutput:
diff --git a/snapshots/session/ptc-read-image/system-prompt.expected.md b/snapshots/session/ptc-read-image/system-prompt.expected.md
index 618fc7e047..dbb8204298 100644
--- a/snapshots/session/ptc-read-image/system-prompt.expected.md
+++ b/snapshots/session/ptc-read-image/system-prompt.expected.md
@@ -135,11 +135,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/session/ptc-turn/system-prompt.expected.md b/snapshots/session/ptc-turn/system-prompt.expected.md
index 3854aa2dca..80c671f372 100644
--- a/snapshots/session/ptc-turn/system-prompt.expected.md
+++ b/snapshots/session/ptc-turn/system-prompt.expected.md
@@ -135,11 +135,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Read a UTF-8 text file and return line-numbered content. */
   read: {
     /** Path to read, resolved by the filesystem backend. */
diff --git a/snapshots/session/pty-tools-sandbox-backend/tool-schemas.expected.json b/snapshots/session/pty-tools-sandbox-backend/tool-schemas.expected.json
index 60c329352a..77611208ff 100644
--- a/snapshots/session/pty-tools-sandbox-backend/tool-schemas.expected.json
+++ b/snapshots/session/pty-tools-sandbox-backend/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/pwsh-tool-turn/tool-schemas.expected.json b/snapshots/session/pwsh-tool-turn/tool-schemas.expected.json
index 498988c06b..c92b5e720f 100644
--- a/snapshots/session/pwsh-tool-turn/tool-schemas.expected.json
+++ b/snapshots/session/pwsh-tool-turn/tool-schemas.expected.json
@@ -172,19 +172,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/ralph-loop/tool-schemas.1.expected.json b/snapshots/session/ralph-loop/tool-schemas.1.expected.json
index 830bda71b2..dfd4c2dda6 100644
--- a/snapshots/session/ralph-loop/tool-schemas.1.expected.json
+++ b/snapshots/session/ralph-loop/tool-schemas.1.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/ralph-loop/tool-schemas.2.expected.json b/snapshots/session/ralph-loop/tool-schemas.2.expected.json
index 830bda71b2..dfd4c2dda6 100644
--- a/snapshots/session/ralph-loop/tool-schemas.2.expected.json
+++ b/snapshots/session/ralph-loop/tool-schemas.2.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/ralph-loop/tool-schemas.expected.json b/snapshots/session/ralph-loop/tool-schemas.expected.json
index 31a9d61ef5..dda5ee11cc 100644
--- a/snapshots/session/ralph-loop/tool-schemas.expected.json
+++ b/snapshots/session/ralph-loop/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/session-query-spill/tool-schemas.expected.json b/snapshots/session/session-query-spill/tool-schemas.expected.json
index 503495145f..3e25a6db8e 100644
--- a/snapshots/session/session-query-spill/tool-schemas.expected.json
+++ b/snapshots/session/session-query-spill/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/subagent-acp-diagnostic/tool-schemas.expected.json b/snapshots/session/subagent-acp-diagnostic/tool-schemas.expected.json
index 7781150adc..93ff550d0f 100644
--- a/snapshots/session/subagent-acp-diagnostic/tool-schemas.expected.json
+++ b/snapshots/session/subagent-acp-diagnostic/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/subagent-agent-preset/tool-schemas.1.expected.json b/snapshots/session/subagent-agent-preset/tool-schemas.1.expected.json
index d0372b37d5..65f758f5e2 100644
--- a/snapshots/session/subagent-agent-preset/tool-schemas.1.expected.json
+++ b/snapshots/session/subagent-agent-preset/tool-schemas.1.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/subagent-agent-preset/tool-schemas.expected.json b/snapshots/session/subagent-agent-preset/tool-schemas.expected.json
index 0a322116cf..b973227972 100644
--- a/snapshots/session/subagent-agent-preset/tool-schemas.expected.json
+++ b/snapshots/session/subagent-agent-preset/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/subagent-child-question-rejection/tool-schemas.expected.json b/snapshots/session/subagent-child-question-rejection/tool-schemas.expected.json
index 4b69cc6622..2fd4909bf1 100644
--- a/snapshots/session/subagent-child-question-rejection/tool-schemas.expected.json
+++ b/snapshots/session/subagent-child-question-rejection/tool-schemas.expected.json
@@ -308,19 +308,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/subagent-no-message-tool/tool-schemas.1.expected.json b/snapshots/session/subagent-no-message-tool/tool-schemas.1.expected.json
index df5cd25bf3..82664f63b2 100644
--- a/snapshots/session/subagent-no-message-tool/tool-schemas.1.expected.json
+++ b/snapshots/session/subagent-no-message-tool/tool-schemas.1.expected.json
@@ -143,19 +143,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/subagent-structured-parent/tool-schemas.1.expected.json b/snapshots/session/subagent-structured-parent/tool-schemas.1.expected.json
index 56c20198a0..3ed127e8d8 100644
--- a/snapshots/session/subagent-structured-parent/tool-schemas.1.expected.json
+++ b/snapshots/session/subagent-structured-parent/tool-schemas.1.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/subagent-structured-parent/tool-schemas.expected.json b/snapshots/session/subagent-structured-parent/tool-schemas.expected.json
index f104dd94bb..15b0f8b29d 100644
--- a/snapshots/session/subagent-structured-parent/tool-schemas.expected.json
+++ b/snapshots/session/subagent-structured-parent/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/subagent-tool-filter/tool-schemas.1.expected.json b/snapshots/session/subagent-tool-filter/tool-schemas.1.expected.json
index 594bfdb967..6a6e4dc947 100644
--- a/snapshots/session/subagent-tool-filter/tool-schemas.1.expected.json
+++ b/snapshots/session/subagent-tool-filter/tool-schemas.1.expected.json
@@ -159,19 +159,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/system-prompt-in-history/tool-schemas.expected.json b/snapshots/session/system-prompt-in-history/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/session/system-prompt-in-history/tool-schemas.expected.json
+++ b/snapshots/session/system-prompt-in-history/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/team-targets/system-prompt.expected.md b/snapshots/session/team-targets/system-prompt.expected.md
index 5f3134b65f..707f784e52 100644
--- a/snapshots/session/team-targets/system-prompt.expected.md
+++ b/snapshots/session/team-targets/system-prompt.expected.md
@@ -11,7 +11,7 @@ The Team Lead and all teammates share the same working directory and filesystem.
 
 Prefer read/edit/write for file changes. If a file operation returns FS_STALE_VERSION, read the current file, rebase your intended change onto the new content, and retry. Bash, formatters, code generators, and scripts are not fully protected by the filesystem version guard; coordinate them explicitly and have the Lead review the final diff and run tests.
 
-Use agent ids as task owners. The Lead can reassign to itself, its direct continuable children, or historical members; other descendants claim tasks themselves. list_agents shows direct contacts by default; descendants scope discovers deeper agents without granting message or assignment authority. inactive means no turn is executing; it does not describe task completion, success, failure, or waiting for other agents. A successful send does not mean the recipient has processed it. Shared-task workflow is list, get, claim with the current revision, perform the work, then complete. Task readiness never starts an owner. Before wait_agent, make sure another required member is running; use send_message first for an inactive direct contact, or coordinate through its parent for a deeper member. wait_agent observes only changes after that call starts, never wakes a member, and returns noProgress immediately when no other member is running. Re-list after wakeup or timeout. The Lead must wait for required teammates before giving the final answer.
+Use agent ids as task owners. The Lead can reassign to itself, its direct continuable children, or historical members; other descendants claim tasks themselves. list_agents shows direct contacts and all reachable continuable descendants; discovery does not grant message or assignment authority. inactive means no turn is executing; it does not describe task completion, success, failure, or waiting for other agents. A successful send does not mean the recipient has processed it. Shared-task workflow is list, get, claim with the current revision, perform the work, then complete. Task readiness never starts an owner. Before wait_agent, make sure another required member is running; use send_message first for an inactive direct contact, or coordinate through its parent for a deeper member. wait_agent observes only changes after that call starts, never wakes a member, and returns noProgress immediately when no other member is running. Re-list after wakeup or timeout. The Lead must wait for required teammates before giving the final answer.
 
 Check the [exit code: N] marker on every bash result; investigate failures before moving on.
 
diff --git a/snapshots/session/team-targets/tool-schemas.expected.json b/snapshots/session/team-targets/tool-schemas.expected.json
index a888f50485..c260c0f74a 100644
--- a/snapshots/session/team-targets/tool-schemas.expected.json
+++ b/snapshots/session/team-targets/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/text-turn/tool-schemas.expected.json b/snapshots/session/text-turn/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/session/text-turn/tool-schemas.expected.json
+++ b/snapshots/session/text-turn/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/web-fetch/tool-schemas.expected.json b/snapshots/session/web-fetch/tool-schemas.expected.json
index 2938f743b0..1c7e8191a1 100644
--- a/snapshots/session/web-fetch/tool-schemas.expected.json
+++ b/snapshots/session/web-fetch/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/workflow-confinement/tool-schemas.expected.json b/snapshots/session/workflow-confinement/tool-schemas.expected.json
index 911b9d96ad..b546a748a7 100644
--- a/snapshots/session/workflow-confinement/tool-schemas.expected.json
+++ b/snapshots/session/workflow-confinement/tool-schemas.expected.json
@@ -245,19 +245,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/workspace-dependencies/tool-schemas.expected.json b/snapshots/session/workspace-dependencies/tool-schemas.expected.json
index 9e17d1d6d8..d2a760c296 100644
--- a/snapshots/session/workspace-dependencies/tool-schemas.expected.json
+++ b/snapshots/session/workspace-dependencies/tool-schemas.expected.json
@@ -200,19 +200,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/session/worktree/tool-schemas.expected.json b/snapshots/session/worktree/tool-schemas.expected.json
index fd2cfdf1aa..c03aa73317 100644
--- a/snapshots/session/worktree/tool-schemas.expected.json
+++ b/snapshots/session/worktree/tool-schemas.expected.json
@@ -262,19 +262,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/web/fresh-round-trip/tool-schemas.expected.json b/snapshots/web/fresh-round-trip/tool-schemas.expected.json
index 6e670bbb61..b591338416 100644
--- a/snapshots/web/fresh-round-trip/tool-schemas.expected.json
+++ b/snapshots/web/fresh-round-trip/tool-schemas.expected.json
@@ -308,19 +308,10 @@
     },
     {
       "name": "list_agents",
-      "description": "List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
+      "description": "List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation.",
       "parameters": {
         "type": "object",
-        "properties": {
-          "scope": {
-            "type": "string",
-            "description": "children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent.",
-            "enum": [
-              "children",
-              "descendants"
-            ]
-          }
-        }
+        "properties": {}
       }
     },
     {
diff --git a/snapshots/web/official-subagent-bundle/system-prompt.expected.md b/snapshots/web/official-subagent-bundle/system-prompt.expected.md
index d26b15e561..693d9cae1b 100644
--- a/snapshots/web/official-subagent-bundle/system-prompt.expected.md
+++ b/snapshots/web/official-subagent-bundle/system-prompt.expected.md
@@ -153,11 +153,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Declare existing files as final deliverables for the user. Use it when the user needs a separate file, especially Office documents, spreadsheets, and slide decks; prefer your final response when that suffices. The user opens the current files; their contents are not copied. */
   present: {
     /** Usually the 1-2 most important deliverables; at most 4 per call. */
diff --git a/snapshots/web/optional-string-editor/system-prompt.expected.md b/snapshots/web/optional-string-editor/system-prompt.expected.md
index 7969fa638f..58a7662e07 100644
--- a/snapshots/web/optional-string-editor/system-prompt.expected.md
+++ b/snapshots/web/optional-string-editor/system-prompt.expected.md
@@ -153,11 +153,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Declare existing files as final deliverables for the user. Use it when the user needs a separate file, especially Office documents, spreadsheets, and slide decks; prefer your final response when that suffices. The user opens the current files; their contents are not copied. */
   present: {
     /** Usually the 1-2 most important deliverables; at most 4 per call. */
diff --git a/snapshots/web/ptc-round/system-prompt.expected.md b/snapshots/web/ptc-round/system-prompt.expected.md
index e45efb4379..1abaf8becf 100644
--- a/snapshots/web/ptc-round/system-prompt.expected.md
+++ b/snapshots/web/ptc-round/system-prompt.expected.md
@@ -153,11 +153,8 @@ interface ToolArgsMap {
     /** Max wait in milliseconds with wait: true. Defaults to and is capped by configuration. */
     timeout_ms?: number;
   } & Record<string, JsonValue>;
-  /** List agents you can message: subagents you started and, when you are a subagent, your parent and your continuable siblings. Rows carry ids, descriptions, and status. running means it is working; inactive means it is not currently working. You will be notified when a subagent finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
-  list_agents: {
-    /** children (default) lists your parent, continuable siblings, and direct children; each accepts send_message in any status. descendants lists the whole tree below you with each entry's parent session id and depth; entries deeper than 1 accept only interrupt_agent. */
-    scope?: "children" | "descendants";
-  } & Record<string, JsonValue>;
+  /** List all your reachable continuable descendants and, when you are a continuable subagent, your parent and continuable siblings. Rows carry ids, descriptions, and status; descendant rows also carry parent ids and depth. You can message your parent, continuable siblings, and direct children. Deeper descendants accept only interrupt_agent. running means it is working; inactive means it is not currently working. You will be notified when a direct child finishes; there is no need to keep checking its status. Use send_message to continue the conversation. */
+  list_agents: Record<string, JsonValue>;
   /** Declare existing files as final deliverables for the user. Use it when the user needs a separate file, especially Office documents, spreadsheets, and slide decks; prefer your final response when that suffices. The user opens the current files; their contents are not copied. */
   present: {
     /** Usually the 1-2 most important deliverables; at most 4 per call. */