{
    "action": "tool_call",
    "reasoning": "I have the treatment arm breakdown from adsl (4 arms, 306 subjects total). Now I need to show how adverse events (the most important metric in a clinical trial safety dataset) vary across these treatment arms. The ae table contains the adverse events, and I need to join it to adsl by USUBJID to get the treatment arm for each event. First, let me verify that USUBJID exists in both tables and can be used as a join key.",
    "tool": "inspect_columns",
    "args": {
        "table": "adsl",
        "columns": [
            "USUBJID",
            "ACTARMCD",
            "ACTARM"
        ]
    }
}