Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Without annotations, the description should provide behavioral details, but it only states the action. It does not mention if it overwrites existing files, whether network access is required, or any side effects. The presence of an output schema partially compensates but does not cover behavioral traits.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.