Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden; 'Return' indicates a read-only operation and 'public' implies no special authentication, while 'canonical' and 'trust-model declarations' give context about the document's authority. It does not discuss caching, rate limits, or failure modes, but for a zero-parameter public getter this is largely sufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.