{
    "action": "tool_call",
    "reasoning": "My previous reply was prose with no tool evidence behind it. I'll pull the profiler's column metadata to ground the cardinality figures for categorical columns.",
    "tool": "query_sql",
    "args": {
        "sql": "SELECT table_name, column_name, phys_type, rough_kind, semantic_role, distinct_count, approx_distinct_count, null_count FROM analytics.column_overview WHERE rough_kind = 'categorical' OR semantic_role ILIKE '%categor%' ORDER BY approx_distinct_count",
        "purpose": "List categorical columns with their distinct counts across all tables",
        "source": "raw"
    }
}