Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden but only states what the tool does ('brings data'), not how it behaves. It lacks details on data freshness, source, format, error handling, or any constraints like rate limits or authentication needs, which are critical for a data-fetching tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.