Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the description need not repeat parameter definitions. It lightly reinforces the meanings of reportType and format by listing examples (profit and loss, trial balance, etc.) and mentioning 'reporting period' for dates, which maps to fromDate/toDate. This adds marginal value over the schema, warranting a baseline 3.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.