Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare it as read-only, non-destructive, and idempotent. The description adds value by specifying the return fields (id, name, permission scope), giving the agent a concrete idea of what to expect. No additional side effects or caveats are necessary for a simple getter.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.