Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the baseline is 3. The description adds meaning beyond the schema by specifying that responses must come from the same prompt template and by enumerating variant dimensions (gender, origin, age, tone), which clarifies expected values for variantId more concretely than the schema examples alone.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.