Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must fully disclose behavior. It only states the conversion action without detailing edge cases, input format constraints (e.g., decimal precision, negative values), or output format. This is a significant gap for a tool that could behave unexpectedly with non-numeric or extreme inputs.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.