Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description provides rich behavioral context beyond annotations: it spends balance, requires authentication, cross-references Wikidata for verification, and returns a proof_id for verification. Annotations already indicate openWorldHint=true and readOnlyHint=false, but the description adds critical details about cost, authentication needs, and verification workflow.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.