Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must fully disclose behavior. It describes the output structure but omits critical behavioral traits such as read-only nature, authentication needs (tokens), error handling, or rate limits. The return type is given but not how the tool behaves in edge cases.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.