{
    "action": "tool_call",
    "reasoning": "My previous reply was not a valid action and cited figures I have no tool results for in this context. I'll re-run the key check, whether sleep_debt_category is a clean function of total_sleep_hours, with one query, and answer only from its result.",
    "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, SUM(CASE WHEN total_sleep_hours < 4 THEN 1 ELSE 0 END) AS rows_under_4h, COUNT(DISTINCT user_id) AS distinct_users FROM raw.bedtime_screentime_sleep_debt GROUP BY sleep_debt_category ORDER BY min_hours",
        "purpose": "Verify whether sleep_debt_category bands overlap on total_sleep_hours and confirm user_id uniqueness per category",
        "source": "raw"
    }
}