{
    "action": "tool_call",
    "reasoning": "Profile the single raw table in one query: row count, key uniqueness, ranges, null counts for all measures and classifiers, and a sanity check on deep+REM percentages.",
    "tool": "query_sql",
    "args": {
        "sql": "SELECT COUNT(*) n, COUNT(DISTINCT user_id) distinct_users, MIN(age) age_min, MAX(age) age_max, COUNT(age) age_nn, MIN(bedtime_phone_minutes) bpm_min, MAX(bedtime_phone_minutes) bpm_max, COUNT(bedtime_phone_minutes) bpm_nn, MIN(screen_brightness_pct) br_min, MAX(screen_brightness_pct) br_max, COUNT(screen_brightness_pct) br_nn, MIN(blue_light_filter_active) bl_min, MAX(blue_light_filter_active) bl_max, MIN(caffeine_post_5pm_mg) caf_min, MAX(caffeine_post_5pm_mg) caf_max, COUNT(caffeine_post_5pm_mg) caf_nn, MIN(physical_activity_min) pa_min, MAX(physical_activity_min) pa_max, COUNT(physical_activity_min) pa_nn, MIN(sleep_latency_min) sl_min, MAX(sleep_latency_min) sl_max, COUNT(sleep_latency_min) sl_nn, MIN(total_sleep_hours) ts_min, MAX(total_sleep_hours) ts_max, COUNT(total_sleep_hours) ts_nn, MIN(deep_sleep_pct) ds_min, MAX(deep_sleep_pct) ds_max, COUNT(deep_sleep_pct) ds_nn, MIN(rem_sleep_pct) rem_min, MAX(rem_sleep_pct) rem_max, COUNT(rem_sleep_pct) rem_nn, SUM(CASE WHEN deep_sleep_pct+rem_sleep_pct>100 THEN 1 ELSE 0 END) deep_rem_over100, MIN(morning_alarm_snoozes) sn_min, MAX(morning_alarm_snoozes) sn_max, COUNT(morning_alarm_snoozes) sn_nn, MIN(next_day_fatigue_score) fat_min, MAX(next_day_fatigue_score) fat_max, COUNT(next_day_fatigue_score) fat_nn, COUNT(gender) g_nn, COUNT(occupation_type) o_nn, COUNT(chronotype) c_nn, COUNT(primary_bedtime_app) a_nn, COUNT(sleep_debt_category) sd_nn FROM raw.bedtime_screentime_sleep_debt",
        "purpose": "Profile ranges, null counts, key uniqueness and sanity checks across all columns",
        "source": "raw"
    }
}