Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It clarifies what "busy" means (jobs in progress), which is genuinely useful, but says nothing about the return shape, whether it is a safe read, throttling, or what counts toward "in progress" — a gap for a status-query tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.