{
    "action": "tool_call",
    "reasoning": "No evidence is in hand for the column-role question, so I'll pull the profiler's column metadata for all five tables in one query before answering.",
    "tool": "query_sql",
    "args": {
        "sql": "SELECT table_name, column_name, phys_type, semantic_role, rough_kind, null_count, distinct_count, uniqueness_score, key_role FROM analytics.column_overview ORDER BY table_name, column_name",
        "purpose": "Profile column types, semantic roles and key roles across all tables",
        "source": "raw"
    }
}