Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the baseline is 3. The tool description itself contains no parameter-level guidance; all parameter semantics are already in the input schema. The extra 'Keep to plain concept terms' note appears in the schema, not the tool description, so no additional value is added.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.