Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of disclosing behavior, but it only states 'check if' without specifying return type, side effects, or error handling. The agent cannot know whether the result is a boolean, a status string, or an object, nor whether any permissions are required.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.