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's feature list maps onto the optional parameters and adds meaning — 'token budgeting' tells you max_context_tokens actually truncates context, and 'citation numbering' tells you cite_sources changes the output text, not just metadata. It does not clarify how chunk.score is used (ordering/filtering), which is the one semantic gap.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.