{
    "action": "tool_call",
    "reasoning": "No evidence is in hand yet, so I'll recompute the key correlations in one query rather than rely on unverified numbers.",
    "tool": "query_sql",
    "args": {
        "sql": "SELECT COUNT(*) AS n, CORR(bedtime_phone_minutes, sleep_latency_min) AS phone_vs_latency, CORR(bedtime_phone_minutes, total_sleep_hours) AS phone_vs_sleep_hours, CORR(bedtime_phone_minutes, next_day_fatigue_score) AS phone_vs_fatigue, CORR(total_sleep_hours, next_day_fatigue_score) AS sleep_hours_vs_fatigue, CORR(sleep_latency_min, next_day_fatigue_score) AS latency_vs_fatigue, CORR(blue_light_filter_active, sleep_latency_min) AS filter_vs_latency, CORR(screen_brightness_pct, sleep_latency_min) AS brightness_vs_latency, CORR(caffeine_post_5pm_mg, total_sleep_hours) AS caffeine_vs_sleep_hours, AVG(CASE WHEN blue_light_filter_active = 1 THEN sleep_latency_min END) AS latency_with_filter, AVG(CASE WHEN blue_light_filter_active = 0 THEN sleep_latency_min END) AS latency_without_filter FROM raw.bedtime_screentime_sleep_debt",
        "purpose": "Verify correlations between phone use, screen settings, caffeine, sleep outcomes and fatigue",
        "source": "raw"
    }
}