Get Schema

Describe the organization's data schema. Returns every table the agent can target, including its semantic category (e.g. raw vs. curated), description, and full column definitions with types, nullability, uniqueness, and foreign-key targets. Each column carries two names: 'name' is what the read and write tools accept, and 'sql_column_name' is the physical column for SQL queries (foreign keys carry an _id suffix). This is the map a parser writes into: use it to plan which tables to populate and how rows link.