-back to the agent as one message that starts with ``[NAME]``. Each model
-call of a subagent has the name in the ``agent`` field of
-``agent/usage.jsonl``.
+back to the agent as one message that starts with ``[NAME]``. The agent
+can send a subagent more messages: a running subagent reads them between
+its tool calls, and a finished one goes on from its log, and its reply
+comes back in the same way. Each model call of a subagent has the name
+in the ``agent`` field of ``agent/usage.jsonl``.