An agent.open.before hook that awaits setMetadata (or any write) on the
agent being opened deadlocks: the write joins the agent's lifecycle lane
behind the open, and the open waits on the hook until it times out. The
hooks reference now says so and shows the supported shape, a write
started without awaiting, which runs right after the open.
Deferred, not in this stack: reject such a write immediately instead of
letting the hook time out. The host knows which plugin hook it is
awaiting for the agent and which channel the write arrives on, so the
rejection can be keyed on "this plugin is inside an open hook for this
agent" without cross-process tagging, and an unrelated client's write
would still wait as it does today.
Mohamed Boudra
5828fd5ce4