Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It reveals the core behavior (URL support check), the output (confidence score), and a pricing detail, but it does not specify the score scale, whether the URL is fetched live, or how failures are handled. This is adequate but not rich.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.