Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations provide key behavioral hints (non-readOnly, non-destructive, idempotent), but the description adds valuable context by specifying it disconnects from an existing connection. It doesn't contradict annotations and clarifies the precondition, though it could mention side effects like terminating ongoing operations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.