Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (readOnlyHint=false, destructiveHint=false, idempotentHint=true), the description adds meaningful behavioral detail: the project stays visible to the workspace, and leaving a project the caller is not in reports not_a_member and changes nothing. This clarifies the non-destructive and effectively idempotent nature. It does not discuss permissions or rate limits, but the annotations already set a clear safety profile.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.