Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must fully disclose behavior. It does not state that the tool is read-only, whether it requires authentication (api_key is optional in schema), or mention rate limits, pagination, or error handling. The word 'aggregated' hints at behavior but lacks depth.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.