Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already indicate readOnlyHint=true and idempotentHint=true, signaling a safe read operation. The description adds value by specifying exactly what metadata is returned (last used, scopes, active status), which goes beyond the annotations and helps the agent understand the tool's output. No contradiction with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.