Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds genuinely new behavioral facts: only currently-active uploads are returned, the payload excludes full text, and uploads expire 24h after upload — which tells the agent results are ephemeral. Return shape is left to the output schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.