Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already convey readOnly, idempotent, and non-destructive behavior. The description adds meaningful context beyond annotations by clarifying that only public, existing published language versions are used, with English fallback. No contradiction with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.