Catalog
User-visible tools
What you see in the conversation is a handful of short bubbles, not the inner loop. Four tools produce them:
Plain assistant text outside these tools is dropped, not rewritten into a canned message. See How Bot works.
Background tasks
task starts work in the background and returns immediately with { ok, id, status: "queued" }. The child then emits task_started, task_progress, and task_completed or task_failed. Children cannot send_to_user and cannot nest another task; everything reports back through the parent.