I need to check which columns have missing values and calculate the percentage for each. Let me query the column metadata to get null counts and total row counts. ```json { "action": "tool_call", "reasoning": "I'll query the analytics.column_overview metadata table to get null_count for all columns in the dataset, along with the table's row count from analytics.table_overview. This will let me calculate the percentage of missing values for each column in a single query.", "tool": "query_sql", "args": { "sql": "SELECT co.table_name, co.column_name, co.null_count, t.row_count, ROUND(100.0 * co.null_count / t.row_count, 2) AS missing_percentage FROM analytics.column_overview co JOIN analytics.table_overview t ON co.table_name = t.table_name WHERE co.null_count > 0 ORDER BY missing_percentage DESC", "purpose": "Find all columns with missing values and calculate the percentage of nulls for each", "source": "raw" } } ```