Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses the matching behavior ('exact name'), scope ('whole schema'), and the return contents (description, valid values, notes, tables, foreign-key roles). However, it doesn't mention what happens if the column is not found, or whether matching is case-sensitive, which are minor gaps. Overall, it provides substantial behavioral context beyond a simple query.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.