Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It discloses that the tool is a polling operation and that statuses eventually reach 'done' or 'error', which is useful. However, it doesn't state whether the operation is read-only, what intermediate statuses may appear, or how errors are surfaced.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.