Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the baseline is 3, but the description adds real value beyond the schema by explaining what the country parameter controls: country-specific layout, mod-97 check digits, and BE/FR national check digits. This helps an agent reason about country-dependent behavior rather than just treating country as an enum value.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.