Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuine behavioral context – currency derives from the reader's language, and whether a fee is fixed/floor/monthly or refundable – but omits ordering guarantees or caching/freshness of pricing.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.