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 enriches parameter meaning: it names the exact search tools that supply cid, clarifies that _rent kinds change output format, and explains how to interpret rent amounts. This goes beyond what the schema alone provides.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.