Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare non-read-only, open-world, idempotent, non-destructive behavior, and the description reinforces idempotency ("idempotent on LinkedIn's side") while adding genuinely new context: it consumes the daily reactions quota and acts on behalf of the connected account. Quota consumption is real behavioral information not present in the annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.