Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate readOnlyHint, openWorldHint, and idempotentHint, covering safety and side-effect expectations. The description adds behavioral context by stating it returns a match score, which is not in the annotations. This is helpful for the agent to know what output to expect. It does not discuss edge cases like no match or ambiguous matches, but the strong annotation coverage reduces the need for further disclosure.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.