Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this as readOnly, non-destructive, and idempotent. The description adds value beyond annotations by specifying exactly what the tool reports (whether connected, which provider, test count, and supported providers when not connected), giving agents a clear picture of the output content without contradicting any hints.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.