{
    "action": "tool_call",
    "reasoning": "No evidence yet, so I'll profile the numeric columns in a single query. This covers the null count, range, mean, median and spread for each measure. It gives the base needed to answer the analytical question.",
    "tool": "query_sql",
    "args": {
        "sql": "SELECT 'age' AS col, COUNT(age) AS n, MIN(age) AS min_v, MAX(age) AS max_v, AVG(age) AS mean_v, MEDIAN(age) AS median_v, STDDEV(age) AS stddev_v FROM raw.bedtime_screentime_sleep_debt UNION ALL SELECT 'bedtime_phone_minutes', COUNT(bedtime_phone_minutes), MIN(bedtime_phone_minutes), MAX(bedtime_phone_minutes), AVG(bedtime_phone_minutes), MEDIAN(bedtime_phone_minutes), STDDEV(bedtime_phone_minutes) FROM raw.bedtime_screentime_sleep_debt UNION ALL SELECT 'screen_brightness_pct', COUNT(screen_brightness_pct), MIN(screen_brightness_pct), MAX(screen_brightness_pct), AVG(screen_brightness_pct), MEDIAN(screen_brightness_pct), STDDEV(screen_brightness_pct) FROM raw.bedtime_screentime_sleep_debt UNION ALL SELECT 'caffeine_post_5pm_mg', COUNT(caffeine_post_5pm_mg), MIN(caffeine_post_5pm_mg), MAX(caffeine_post_5pm_mg), AVG(caffeine_post_5pm_mg), MEDIAN(caffeine_post_5pm_mg), STDDEV(caffeine_post_5pm_mg) FROM raw.bedtime_screentime_sleep_debt UNION ALL SELECT 'physical_activity_min', COUNT(physical_activity_min), MIN(physical_activity_min), MAX(physical_activity_min), AVG(physical_activity_min), MEDIAN(physical_activity_min), STDDEV(physical_activity_min) FROM raw.bedtime_screentime_sleep_debt UNION ALL SELECT 'sleep_latency_min', COUNT(sleep_latency_min), MIN(sleep_latency_min), MAX(sleep_latency_min), AVG(sleep_latency_min), MEDIAN(sleep_latency_min), STDDEV(sleep_latency_min) FROM raw.bedtime_screentime_sleep_debt UNION ALL SELECT 'total_sleep_hours', COUNT(total_sleep_hours), MIN(total_sleep_hours), MAX(total_sleep_hours), AVG(total_sleep_hours), MEDIAN(total_sleep_hours), STDDEV(total_sleep_hours) FROM raw.bedtime_screentime_sleep_debt UNION ALL SELECT 'deep_sleep_pct', COUNT(deep_sleep_pct), MIN(deep_sleep_pct), MAX(deep_sleep_pct), AVG(deep_sleep_pct), MEDIAN(deep_sleep_pct), STDDEV(deep_sleep_pct) FROM raw.bedtime_screentime_sleep_debt UNION ALL SELECT 'rem_sleep_pct', COUNT(rem_sleep_pct), MIN(rem_sleep_pct), MAX(rem_sleep_pct), AVG(rem_sleep_pct), MEDIAN(rem_sleep_pct), STDDEV(rem_sleep_pct) FROM raw.bedtime_screentime_sleep_debt UNION ALL SELECT 'morning_alarm_snoozes', COUNT(morning_alarm_snoozes), MIN(morning_alarm_snoozes), MAX(morning_alarm_snoozes), AVG(morning_alarm_snoozes), MEDIAN(morning_alarm_snoozes), STDDEV(morning_alarm_snoozes) FROM raw.bedtime_screentime_sleep_debt UNION ALL SELECT 'next_day_fatigue_score', COUNT(next_day_fatigue_score), MIN(next_day_fatigue_score), MAX(next_day_fatigue_score), AVG(next_day_fatigue_score), MEDIAN(next_day_fatigue_score), STDDEV(next_day_fatigue_score) FROM raw.bedtime_screentime_sleep_debt",
        "purpose": "Profile all numeric measures in one query: counts, range, mean, median, stddev",
        "source": "raw"
    }
}