Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the transparency burden. It discloses the compatibility boundary and the exclusive parameter requirement, but it does not describe behavior for invalid combinations (both/neither model and encoding) or tokenization nuances beyond the schema. This is adequate but not rich.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.