Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already mark it as read-only, idempotent, and non-destructive, so the baseline for additional disclosure is lowered. The description adds value by explaining the return payload in two specific states (all connected vs. missing credentials), which is not conveyed by the schema or annotations. No contradiction exists.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.