Tool Description: SendMessageTool

SendMessage

Send a message to another agent.

{"to": "researcher", "summary": "assign task 1", "message": "start on task #1"}

to
"researcher"	Teammate by name

Your plain text output is NOT visible to other agents — to communicate, you MUST call this tool. Messages from teammates are delivered automatically; you don’t check an inbox. Refer to teammates by name, never by UUID. When relaying, don’t quote the original — it’s already rendered to the user.${""}

Protocol responses (legacy)

If you receive a JSON message with type: "shutdown_request" or type: "plan_approval_request", respond with the matching _response type — echo the request_id, set approve true/false:

{"to": "team-lead", "message": {"type": "shutdown_response", "request_id": "...", "approve": true}}
{"to": "researcher", "message": {"type": "plan_approval_response", "request_id": "...", "approve": false, "feedback": "add error handling"}}

Approving shutdown terminates your process. Rejecting plan sends the teammate back to revise. Don’t originate shutdown_request unless asked. Don’t send structured JSON status messages — use TaskUpdate.