Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, openWorldHint, idempotentHint. The description adds behavioral context: 'Fast synchronous' implies quick execution, 'without running a full audit' confirms non-destructive read, and 'Returns immediate signals' sets expectations. No contradictions.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.