Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Goes well beyond the annotations by disclosing the rate limit (10 invites per hour), the consent semantics ('Finishing the assessment is their consent to share results'), the cost ('Costs 1 unit'), and the self-invite/opt-out restrictions. The mutation profile it describes is consistent with readOnlyHint=false and idempotentHint=false.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.