Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of explaining behavior. It clearly states what the tool returns and that the output contains field metadata, but it does not explicitly note that the tool is read-only, whether authentication is needed, or how the fields are structured in the response. For a simple field-listing tool this is adequate but not fully transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.