I need to identify categorical columns and count their distinct values. Let me start by getting an overview of the dataset's columns to understand which ones are categorical. ```json { "action": "tool_call", "reasoning": "I need to understand the column landscape first. The dataset has 43 tables with over 2 million rows total. I'll read the topology insight to understand the structure and identify categorical columns across the dataset.", "tool": "read_insight", "args": { "section": "topology" } } ```