{
    "action": "tool_call",
    "reasoning": "Determine the time coverage of each table's date/year column. Date may be text, so I cast to VARCHAR and check type and non-null counts.",
    "tool": "query_sql",
    "args": {
        "sql": "SELECT 'raw_kaggle' AS tbl, typeof(\"Date\") AS dtype, CAST(MIN(\"Date\") AS VARCHAR) AS min_date, CAST(MAX(\"Date\") AS VARCHAR) AS max_date, COUNT(\"Date\") AS non_null FROM raw.raw_kaggle UNION ALL SELECT 'return_kaggle', typeof(\"Date\"), CAST(MIN(\"Date\") AS VARCHAR), CAST(MAX(\"Date\") AS VARCHAR), COUNT(\"Date\") FROM raw.return_kaggle UNION ALL SELECT 'serve_kaggle', typeof(\"Date\"), CAST(MIN(\"Date\") AS VARCHAR), CAST(MAX(\"Date\") AS VARCHAR), COUNT(\"Date\") FROM raw.serve_kaggle UNION ALL SELECT 'players_tournament_man_ (year)', typeof(\"year\"), CAST(MIN(\"year\") AS VARCHAR), CAST(MAX(\"year\") AS VARCHAR), COUNT(\"year\") FROM raw.players_tournament_man_",
        "purpose": "Determine the time coverage of each table's date/year column",
        "source": "raw"
    }
}