Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the burden of behavioral disclosure. It states that the tool 'Returns' a guide, implying a read-only, non-mutating operation. It adds context about the autonomous nature and lack of web UI, which clarifies expectations. However, it does not go into further depth about potential side effects or required auth, but for a simple retrieval tool this is sufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.