Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and idempotentHint=false. The description usefully adds that only joined groups are returned (not discoverable/created ones) and what fields come back, but it does not explain why the call is non-idempotent, whether results are ordered, or how they behave for large group lists. With annotations covering the safety profile, this is adequate but thin.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.