Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is fully structured. The description adds nothing beyond this — no disclosure of lookup failure behavior, rate limits, or whether the username must be an existing public handle. For a tool whose annotations carry the safety story, it contributes no extra behavioral context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.