feat: add agents_list tool

docs/tools/index.md

@@ -188,6 +188,13 @@ Notes:
 - `sessions_send` runs a reply‑back ping‑pong (reply `REPLY_SKIP` to stop; max turns via `session.agentToAgent.maxPingPongTurns`, 0–5).
 - After the ping‑pong, the target agent runs an **announce step**; reply `ANNOUNCE_SKIP` to suppress the announcement.
 
+### `agents_list`
+List agent ids that the current session may target with `sessions_spawn`.
+
+Notes:
+- Result is restricted to per-agent allowlists (`routing.agents.<agentId>.subagents.allowAgents`).
+- When `["*"]` is configured, the tool includes all configured agents and marks `allowAny: true`.
+
 ### `discord`
 Send Discord reactions, stickers, or polls.
 

docs/tools/subagents.md

@@ -32,6 +32,9 @@ Tool params:
 Allowlist:
 - `routing.agents.<agentId>.subagents.allowAgents`: list of agent ids that can be targeted via `agentId` (`["*"]` to allow any). Default: only the requester agent.
 
+Discovery:
+- Use `agents_list` to see which agent ids are currently allowed for `sessions_spawn`.
+
 Auto-archive:
 - Sub-agent sessions are automatically archived after `agent.subagents.archiveAfterMinutes` (default: 60).
 - Archive uses `sessions.delete` and renames the transcript to `*.deleted.<timestamp>` (same folder).