Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It adds relevant context by explaining that the guesses are 'rich in common, distinct letters,' giving insight into the output's nature. However, it does not disclose the return format (e.g., a list of strings), language constraints, or how max_results affects the behavior. It is partially transparent but lacks completeness.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.