Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (which only say the tool is not read-only and not destructive), the description discloses the key behavioral trait that the switch persists across sessions, and the access requirement that the caller must be a member. No contradiction with annotations exists, as the readOnlyHint=false is consistent with a state-changing operation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.