Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the behavioral burden, but it only says 'Get detailed health status' without explaining what subsystems are covered, whether the call is expensive or real-time, or what form the result takes. The read-only nature is implied by 'Get', but little else is disclosed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.