Revert "feat(core): add dynamic swarm worker tool (#3433)" (#3468)

This reverts commit f7ebc372f1.

docs/developers/tools/_meta.ts

@@ -5,7 +5,6 @@ export default {
   shell: 'Shell',
   'todo-write': 'Todo Write',
   task: 'Task',
-  swarm: 'Swarm',
   'exit-plan-mode': 'Exit Plan Mode',
   'web-fetch': 'Web Fetch',
   'web-search': 'Web Search',

docs/developers/tools/introduction.md

@@ -51,7 +51,6 @@ Qwen Code's built-in tools can be broadly categorized as follows:
 - **[Memory Tool](./memory.md) (`save_memory`):** For saving and recalling information across sessions.
 - **[Todo Write Tool](./todo-write.md) (`todo_write`):** For creating and managing structured task lists during coding sessions.
 - **[Task Tool](./task.md) (`task`):** For delegating complex tasks to specialized subagents.
-- **[Swarm Tool](./swarm.md) (`swarm`):** For running many independent lightweight workers in parallel and aggregating their results.
 - **[Exit Plan Mode Tool](./exit-plan-mode.md) (`exit_plan_mode`):** For exiting plan mode and proceeding with implementation.
 
 Additionally, these tools incorporate:

docs/developers/tools/swarm.md

@@ -1,102 +0,0 @@
-# Swarm Tool (`swarm`)
-
-Use `swarm` to run many independent, simple tasks through ephemeral worker
-agents and return a structured aggregate result to the parent agent.
-
-Swarm is intended for map-reduce style work:
-
-- analyzing many files independently
-- processing chunks of a large data file
-- running independent searches where the first successful result is enough
-- collecting per-item summaries, counts, or validation results
-
-For a few complex role-based tasks, use the [`task`](./task.md) tool instead.
-For model comparison on the same task, use Agent Arena.
-
-## Arguments
-
-- `description` (string, required): Short description of the overall swarm job.
-- `tasks` (array, required): Independent tasks. Each task becomes one worker.
-  - `id` (string, optional): Stable identifier returned in results.
-  - `description` (string, required): Short per-worker description.
-  - `prompt` (string, required): Complete instructions for the worker.
-- `mode` (`wait_all` or `first_success`, optional): Defaults to `wait_all`.
-- `max_concurrency` (number, optional): Maximum workers to run at once.
-- `max_turns` (number, optional): Maximum model/tool turns per worker.
-  Defaults to `8`.
-- `timeout_seconds` (number, optional): Per-worker wall-clock timeout.
-- `worker_system_prompt` (string, optional): Shared worker system prompt.
-- `allowed_tools` (string array, optional): Tool allowlist for workers.
-- `disallowed_tools` (string array, optional): Tools removed from workers.
-
-If `max_concurrency` is omitted, Qwen Code uses
-`QWEN_CODE_MAX_SWARM_CONCURRENCY`, then `QWEN_CODE_MAX_TOOL_CONCURRENCY`, then
-`10`.
-
-## Result
-
-The tool returns JSON to the parent agent with:
-
-- `summary.total`
-- `summary.completed`
-- `summary.failed`
-- `summary.cancelled`
-- `summary.notStarted`
-- `results[]` with one entry per task, including `taskId`, `status`, `output`
-  or `error`, duration, and execution stats when available
-
-Individual worker failures do not abort the whole swarm. The parent agent is
-responsible for reading the aggregate result and presenting the final answer.
-
-## Examples
-
-Analyze files in parallel:
-
-```text
-swarm(
-  description="Extract function names",
-  tasks=[
-    {
-      id="src/a.ts",
-      description="Analyze src/a.ts",
-      prompt="Read /repo/src/a.ts and return the exported function names."
-    },
-    {
-      id="src/b.ts",
-      description="Analyze src/b.ts",
-      prompt="Read /repo/src/b.ts and return the exported function names."
-    }
-  ],
-  max_concurrency=10
-)
-```
-
-Use first successful result:
-
-```text
-swarm(
-  description="Find API route definition",
-  mode="first_success",
-  tasks=[
-    {
-      description="Search routes directory",
-      prompt="Search /repo/src/routes for the user creation route."
-    },
-    {
-      description="Search controllers directory",
-      prompt="Search /repo/src/controllers for the user creation route."
-    }
-  ]
-)
-```
-
-## Notes
-
-Workers are lightweight and ephemeral: they are spawned, execute one task,
-return a result, and are cleaned up. Workers cannot spawn further subagents or
-cron jobs.
-
-Swarm workers run concurrently, so interactive permission prompts are avoided.
-Permission hooks can still approve actions, and permissive approval modes still
-apply where configured. Prefer read-only or disjoint file scopes for swarm
-tasks.