Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema covers 100% of parameters with a simple description (工事名やキーワード), so baseline is 3. The description adds value by providing concrete example queries (外壁塗装, 浴室, 給湯器) and clarifying that Japanese keywords work best, which helps the agent form effective queries. This enrichment justifies one point above baseline.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.