Run a read-only SQL query against YugabyteDB and return results as JSON. The query is executed inside a READ ONLY transaction so writes are rejected. Results are returned as a JSON array where each element is a row object with column names as keys.

List all tables in a YugabyteDB database, including column schemas and row counts. CALL THIS FIRST to understand the database structure before writing queries. Returns every table in the given schema with: table name, column definitions (name and data type), and total row count.