{
    "action": "tool_call",
    "reasoning": "I need to list all columns, their data types, and their meanings. I will query the analytics.column_overview table to get this metadata for the epoch_ai_benchmarks table.",
    "tool": "query_sql",
    "args": {
        "purpose": "Get column metadata",
        "source": "raw",
        "sql": "SELECT column_name, phys_type, semantic_role, rough_kind FROM analytics.column_overview WHERE table_name = 'epoch_ai_benchmarks'"
    }
}