{
    "action": "tool_call",
    "reasoning": "Confirm the grain (one row per stock per day) and show a sample and coverage with one query.",
    "tool": "query_sql",
    "args": {
        "sql": "SELECT COUNT(*) AS n_rows, COUNT(DISTINCT company_name) AS n_companies, COUNT(DISTINCT stock_name) AS n_tickers, MIN(date) AS first_date, MAX(date) AS last_date, COUNT(*) - COUNT(DISTINCT (stock_name || '|' || CAST(date AS VARCHAR))) AS duplicate_key_rows FROM raw.semi_conductor_se",
        "purpose": "Profile dataset size, entities, date range and uniqueness of the (stock_name, date) grain",
        "source": "raw"
    }
}