Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the transparency burden. It discloses the cost per query ($0.25) and indicates the data is 'active' US operations, implying current status rather than historical. However, it does not describe any limitations, data sources, or authentication requirements, which are typical behavioral expectations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.