Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the burden of behavioral disclosure. 'Check' clearly implies a read-only operation, and the description details what information is returned. However, it does not mention edge cases, error behavior, or limitations, such as what happens if neither parameter is provided.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.