Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The readOnlyHint=true annotation already establishes this is a safe read, so the description carries less burden. It adds the REST endpoint mapping, but says nothing about what a query status can be, whether results are paginated, or how many queries are returned — the behavior of a polling endpoint is left implicit.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.