Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, and the schema itself already documents formats, constraints, enums, and special cases (e.g., notes required for 'other', PII exclusion). The description adds no significant parameter-level meaning beyond restating the 30-day requirement already in the schema, so the baseline of 3 applies.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.