Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so all four parameters (model, prompt, system, max_tokens) are already documented in the schema. The description does not add any parameter-specific guidance beyond what's there. Per the rubric, a baseline of 3 is correct when the schema handles the documentation.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.