{
    "action": "tool_call",
    "reasoning": "I need to retrieve the columns, their data types, and their semantic meanings (roles) for the dataset. I will query the analytics.column_overview table to get this information for the main table, 'cleandata'.",
    "tool": "query_sql",
    "args": {
        "purpose": "Get columns, types, and meanings for cleandata",
        "source": "raw",
        "sql": "SELECT column_name, phys_type, semantic_role FROM analytics.column_overview WHERE table_name = 'cleandata'"
    }
}