Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover safety (readOnly, idempotent, non-destructive). The description adds value by explaining the 'curated index of vetted, peer-reviewed' nature and the return fields. No contradiction, and it enriches the behavioral context beyond the annotation flags.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.