Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral disclosure burden. It signals an introspection/read-only operation and describes the returned field attributes, including the conditional 'where there are any' for options. However, it never explicitly states the output format (e.g., list of field objects) or that the tool has no side effects, so some behavioral detail 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.