Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, so the agent knows the safety profile. The description adds nothing beyond them: it does not say whether the removal revokes the user's roles/project access, whether it can be undone or re-added, what errors occur for an unknown id, or how it relates to projects_add_member. Note a mild tension between 'Removes' and destructiveHint=false, but readOnlyHint correctly marks this as a write.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.