Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It does disclose one genuinely valuable and non-obvious trait — that the value is *reported* state and 'physical effect is not verified' — warning the agent not to treat it as confirmed actuation. However, it omits permissions, error behavior, and how 'freshness' is expressed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.