```json { "action": "tool_call", "reasoning": "The question asks for the dataset's purpose and grain (what a single row represents). The DATASET CARD shows this is a Zomato restaurant dataset with 9,551 rows in one table. The ONT CARD already indicates the grain is 'one row per restaurant listing; key = Restaurant ID' and the nature is 'observational'. However, I should read the overview insight section to get a fuller narrative description of what the dataset is about, its context, and confirm the row-level grain with more detail.", "tool": "read_insight", "args": { "section": "overview" } } ```