Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations only provide negative hints, so the description carries the burden of explaining behavior. It usefully discloses that the note is visible to the whole team, is authored by the MCP key's user, and is added to an existing thread. It does not mention idempotency or failure modes, but the core behavioral effect is well covered.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.