Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema provides only types and constraints, not descriptions, so schema_description_coverage is essentially zero. The description adds meaning only for 'prompt' by saying the track is created 'from a text prompt,' but it entirely ignores the optional parameters: style, lyrics, instrumental, and duration_seconds. Since the schema carries no semantics, the description needed to compensate more and did not.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.