Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does add a meaningful behavioral detail: pausing stops new work rather than necessarily halting current work. However, it does not disclose reversibility, idempotency, or effects on in-flight tasks, which are relevant for a lifecycle mutation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.