Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden for behavioral disclosure. It states the action (cancel) but does not disclose side effects, irreversibility, error behavior, or prerequisites. An agent cannot infer what happens if the order is already filled, whether cancellation is permanent, or what the response contains.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.