Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
There are no annotations, so the description must disclose behavioral traits itself. 'Create a bill payment' only conveys mutation; it says nothing about whether the bill's status changes, what side effects occur, required permissions, or error behavior. This is a significant gap for a write operation with zero annotation coverage.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.