Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden, yet it discloses nothing beyond the implied read-only nature of "search." No mention of result limits, pagination, ranking, or whether unfiltered searches are allowed, all of which matter for a tool with zero required parameters.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.