{
    "action": "tool_call",
    "reasoning": "I have the row and column counts from step-0. Now I need to determine the time period coverage. I'll query for temporal columns across all tables to find date/timestamp ranges.",
    "tool": "query_sql",
    "purpose": "Find temporal columns and their min/max values to determine dataset time coverage",
    "args": {
        "sql": "SELECT table_name, column_name, phys_type, MIN(CAST(column_name AS VARCHAR)) as earliest, MAX(CAST(column_name AS VARCHAR)) as latest FROM analytics.column_overview WHERE phys_type IN ('TIMESTAMP', 'DATE', 'TIMESTAMP WITH TIME ZONE') OR column_name LIKE '%_at' OR column_name LIKE '%_date' OR column_name LIKE 'date_%' GROUP BY table_name, column_name, phys_type ORDER BY table_name, column_name LIMIT 50",
        "source": "raw"
    }
}