Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With one parameter at 100% schema description coverage, the schema already carries the meaning, so baseline 3 applies. The description does add marginal value by expanding what counts as a valid term (ingredient names, substitutes, techniques, glassware) and by enumerating the sub-fields returned per term type, but it adds no syntax or format detail beyond the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.