feat(delegate): remove model-facing toolsets arg — subagents always inherit parent's (#56386)

The model could pass `toolsets` (top-level and per-task) to delegate_task,
letting it choose which toolsets a subagent got. Toolset selection is a
capability-scoping decision the model should not control; subagents inherit
the parent's enabled toolsets, period.

- Remove `toolsets` from the delegate_task() signature, the registry handler,
  the top-level + per-task JSON schema, and the live dispatch path
  (run_agent._dispatch_delegate_task — this forwarded it on every model call).
- Single-task and per-task child builds now pass toolsets=None so
  _build_child_agent resolves to pure parent inheritance.
- Drop the now-dead _SUBAGENT_TOOLSETS / _TOOLSET_LIST_STR schema-hint block.
- _build_child_agent keeps its internal toolsets param + intersection helpers
  (internal API; fed the inherited value only).
- Tests: schema assertions flipped to assertNotIn; added a regression test
  proving the dispatch path never forwards a smuggled model `toolsets`.
- Docs: update delegate_task signature refs in the autonomous-ai-agents skill.

run_agent.py

@@ -5621,7 +5621,6 @@ class AIAgent:
         return _delegate_task(
             goal=function_args.get("goal"),
             context=function_args.get("context"),
-            toolsets=function_args.get("toolsets"),
             tasks=function_args.get("tasks"),
             max_iterations=function_args.get("max_iterations"),
             acp_command=function_args.get("acp_command"),

skills/autonomous-ai-agents/hermes-agent/SKILL.md

@@ -706,7 +706,7 @@ here; full developer notes live in `AGENTS.md`, user-facing docs under
 
 Spawn a subagent with an isolated context + terminal session.
 
-- **Single:** `delegate_task(goal, context, toolsets)`.
+- **Single:** `delegate_task(goal, context)`.
 - **Batch:** `delegate_task(tasks=[{goal, ...}, ...])` runs children in
   parallel, capped by `delegation.max_concurrent_children` (default 3).
 - **Background:** `delegate_task(background=true)` returns a handle

tests/tools/test_async_delegation.py

@@ -262,7 +262,7 @@ def test_delegate_task_background_routes_async_and_does_not_block(monkeypatch):
     monkeypatch.setattr(dt, "_run_single_child", slow_child)
     monkeypatch.setattr(dt, "_resolve_delegation_credentials", lambda *a, **k: creds)
     out = dt.delegate_task(
-        goal="the real task", context="ctx", toolsets=["web"],
+        goal="the real task", context="ctx",
         background=True, parent_agent=parent,
     )
 
@@ -422,6 +422,30 @@ def test_run_agent_dispatch_forces_background():
         assert captured["background"] is False
 
 
+def test_dispatch_never_forwards_model_toolsets():
+    """The model has no toolsets argument — subagents always inherit the
+    parent's toolsets. Even if a model smuggles a `toolsets` key into the
+    tool-call args, the live dispatch path must NOT forward it to
+    delegate_task (which no longer accepts it) and must not crash."""
+    from unittest.mock import patch
+    import run_agent
+
+    class _FakeAgent:
+        _delegate_depth = 0
+
+    captured = {}
+
+    def _fake_delegate(**kwargs):
+        captured.update(kwargs)
+        return "{}"
+
+    with patch("tools.delegate_tool.delegate_task", _fake_delegate):
+        run_agent.AIAgent._dispatch_delegate_task(
+            _FakeAgent(), {"goal": "x", "toolsets": ["web", "terminal"]}
+        )
+    assert "toolsets" not in captured
+
+
 def test_delegate_task_background_detaches_child_from_parent(monkeypatch):
     """A background child must NOT remain in parent._active_children —
     otherwise parent-turn interrupts / cache evicts / session close would

tests/tools/test_delegate.py

@@ -69,7 +69,11 @@ class TestDelegateRequirements(unittest.TestCase):
         self.assertIn("goal", props)
         self.assertIn("tasks", props)
         self.assertIn("context", props)
-        self.assertIn("toolsets", props)
+        # toolsets is intentionally NOT exposed to the model — subagents always
+        # inherit the parent's toolsets. Letting the model name toolsets was a
+        # capability-selection surface the model should not control.
+        self.assertNotIn("toolsets", props)
+        self.assertNotIn("toolsets", props["tasks"]["items"]["properties"])
         # max_iterations is intentionally NOT exposed to the model — it's
         # config-authoritative via delegation.max_iterations so users get
         # predictable budgets.

tools/delegate_tool.py

@@ -111,24 +111,9 @@ def _get_subagent_approval_callback():
         return _subagent_auto_approve
     return _subagent_auto_deny
 
-# Build a description fragment listing toolsets available for subagents.
-# Excludes toolsets where ALL tools are blocked, composite/platform toolsets
-# (hermes-* prefixed), and scenario toolsets.
-#
-# NOTE: "delegation" is in this exclusion set so the subagent-facing
-# capability hint string (_TOOLSET_LIST_STR) doesn't advertise it as a
-# toolset to request explicitly — the correct mechanism for nested
-# delegation is role='orchestrator', which re-adds "delegation" in
-# _build_child_agent regardless of this exclusion.
-_EXCLUDED_TOOLSET_NAMES = frozenset({"debugging", "safe", "delegation", "rl"})
-_SUBAGENT_TOOLSETS = sorted(
-    name
-    for name, defn in TOOLSETS.items()
-    if name not in _EXCLUDED_TOOLSET_NAMES
-    and not name.startswith("hermes-")
-    and not all(t in DELEGATE_BLOCKED_TOOLS for t in defn.get("tools", []))
-)
-_TOOLSET_LIST_STR = ", ".join(f"'{n}'" for n in _SUBAGENT_TOOLSETS)
+# NOTE: nested delegation is granted by role='orchestrator' (which re-adds the
+# "delegation" toolset in _build_child_agent), NOT by the model naming toolsets
+# — the model has no toolsets argument. Subagents inherit the parent's toolsets.
 
 _DEFAULT_MAX_CONCURRENT_CHILDREN = 3
 # One-shot guard: the high-concurrency cost advisory is emitted at most once
@@ -2354,7 +2339,6 @@ def _recover_tasks_from_json_string(
 def delegate_task(
     goal: Optional[str] = None,
     context: Optional[str] = None,
-    toolsets: Optional[List[str]] = None,
     tasks: Optional[List[Dict[str, Any]]] = None,
     max_iterations: Optional[int] = None,
     acp_command: Optional[str] = None,
@@ -2461,9 +2445,7 @@ def delegate_task(
             )
         task_list = tasks
     elif goal and isinstance(goal, str) and goal.strip():
-        task_list = [
-            {"goal": goal, "context": context, "toolsets": toolsets, "role": top_role}
-        ]
+        task_list = [{"goal": goal, "context": context, "role": top_role}]
     else:
         return tool_error("Provide either 'goal' (single task) or 'tasks' (batch).")
 
@@ -2507,7 +2489,9 @@ def delegate_task(
                 task_index=i,
                 goal=t["goal"],
                 context=t.get("context"),
-                toolsets=t.get("toolsets") or toolsets,
+                # Subagents always inherit the parent's toolsets; the model
+                # cannot choose or narrow them (no model-facing toolsets arg).
+                toolsets=None,
                 model=creds["model"],
                 max_iterations=effective_max_iter,
                 task_count=n_tasks,
@@ -2848,7 +2832,9 @@ def delegate_task(
         dispatch = dispatch_async_delegation_batch(
             goals=_goals,
             context=context,
-            toolsets=toolsets,
+            # Metadata for the completion block only; subagents inherit the
+            # parent's toolsets (no model-facing toolsets arg).
+            toolsets=None,
             role=top_role,
             model=creds["model"],
             session_key=_session_key,
@@ -3387,18 +3373,6 @@ DELEGATE_TASK_SCHEMA = {
                     "specific you are, the better the subagent performs."
                 ),
             },
-            "toolsets": {
-                "type": "array",
-                "items": {"type": "string"},
-                "description": (
-                    "Toolsets to enable for this subagent. "
-                    "Default: inherits your enabled toolsets. "
-                    f"Available toolsets: {_TOOLSET_LIST_STR}. "
-                    "Common patterns: ['terminal', 'file'] for code work, "
-                    "['web'] for research, ['browser'] for web interaction, "
-                    "['terminal', 'file', 'web'] for full-stack tasks."
-                ),
-            },
             "tasks": {
                 "type": "array",
                 "items": {
@@ -3409,11 +3383,6 @@ DELEGATE_TASK_SCHEMA = {
                             "type": "string",
                             "description": "Task-specific context",
                         },
-                        "toolsets": {
-                            "type": "array",
-                            "items": {"type": "string"},
-                            "description": f"Toolsets for this specific task. Available: {_TOOLSET_LIST_STR}. Use 'web' for network access, 'terminal' for shell, 'browser' for web interaction.",
-                        },
                         "acp_command": {
                             "type": "string",
                             "description": (
@@ -3512,7 +3481,6 @@ registry.register(
     handler=lambda args, **kw: delegate_task(
         goal=args.get("goal"),
         context=args.get("context"),
-        toolsets=args.get("toolsets"),
         tasks=args.get("tasks"),
         max_iterations=args.get("max_iterations"),
         acp_command=args.get("acp_command"),

website/docs/user-guide/skills/bundled/autonomous-ai-agents/autonomous-ai-agents-hermes-agent.md

@@ -647,7 +647,7 @@ here; full developer notes live in `AGENTS.md`, user-facing docs under
 Synchronous subagent spawn — the parent waits for the child's summary
 before continuing its own loop. Isolated context + terminal session.
 
-- **Single:** `delegate_task(goal, context, toolsets)`.
+- **Single:** `delegate_task(goal, context)`.
 - **Batch:** `delegate_task(tasks=[{goal, ...}, ...])` runs children in
   parallel, capped by `delegation.max_concurrent_children` (default 3).
 - **Roles:** `leaf` (default; cannot re-delegate) vs `orchestrator`

website/i18n/zh-Hans/docusaurus-plugin-content-docs/current/user-guide/skills/bundled/autonomous-ai-agents/autonomous-ai-agents-hermes-agent.md

@@ -633,7 +633,7 @@ terminal(command="tmux new-session -d -s resumed 'hermes --resume 20260225_14305
 
 同步子 agent 生成——父 agent 等待子 agent 的摘要后再继续自身循环。隔离的上下文和终端会话。
 
-- **单个：** `delegate_task(goal, context, toolsets)`。
+- **单个：** `delegate_task(goal, context)`。
 - **批量：** `delegate_task(tasks=[{goal, ...}, ...])` 并行运行子任务，上限由 `delegation.max_concurrent_children`（默认 3）控制。
 - **角色：** `leaf`（默认；不能再委派）vs `orchestrator`（可以生成自己的 worker，受 `delegation.max_spawn_depth` 限制）。
 - **非持久化。** 如果父 agent 被中断，子 agent 会被取消。对于必须在当前轮次之后继续的工作，使用 `cronjob` 或 `terminal(background=True, notify_on_complete=True)`。