Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% so parameters are documented in schema. Description adds value by clarifying that query accepts both CSS selectors and visible text, and by summarizing the return fields (tag, text, name, type, href). This supplements the schema definitions effectively.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.