Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It adds a meaningful behavioral guarantee ('Page content is not stored') and states the output fields. However, it does not disclose whether a network request is made, error behavior, redirect handling, or how the json and zone inputs are processed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.