Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover safety (read-only, idempotent), and the description adds behavioral details: the search scope (~10,000), the specific return fields (codes, titles, dates, time range), and the fact that it does not return the actual numbers, requiring a follow-up get_dataset call. No contradictions.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.