Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior. The description adds meaningful context beyond that: results are ordered newest first, pinned items appear on top, and returned ids are reusable as library_file_id in other tools. It does not cover pagination or limit behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.