Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations indicate destructiveHint: true and readOnlyHint: false, which strongly suggest the tool modifies state. However, the description describes a read-only retrieval ('Get live currency exchange rates', 'Returns current mid-market rates'), creating a clear contradiction. The description fails to explain the potential destructive side effects or why these annotations exist.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.