Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the transparency burden. It discloses the cost per call and the scope limitation (no full-page content), which is useful. Yet it omits other behaviors such as error handling, authentication requirements, or rate limits, which are relevant for a paid API call.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.