Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the readOnly/openWorld/idempotent annotations, the description discloses valuable behavioral nuances: agent-labeled rows require include_unverified=true and remain labeled, pending event_links carry human_verified=false and review_status=pending_human_review, and interpreted fields like efficacy or PoS are never returned. This goes well beyond the structured annotation hints.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.