{
    "action": "tool_call",
    "reasoning": "No tool results are visible in my evidence, so I can't cite the earlier numbers. I'll re-verify the main finding, how sleep_debt_category relates to total_sleep_hours, plus key counts and nulls, in one query before answering.",
    "tool": "query_sql",
    "args": {
        "sql": "SELECT sleep_debt_category, COUNT(*) AS n, MIN(total_sleep_hours) AS min_hours, MAX(total_sleep_hours) AS max_hours, AVG(total_sleep_hours) AS avg_hours, COUNT(DISTINCT user_id) AS distinct_users, SUM(CASE WHEN total_sleep_hours IS NULL THEN 1 ELSE 0 END) AS null_hours FROM raw.bedtime_screentime_sleep_debt GROUP BY sleep_debt_category ORDER BY min_hours",
        "purpose": "Check whether sleep_debt_category ranges on total_sleep_hours overlap, and confirm row and user counts and nulls",
        "source": "raw"
    }
}