Table schema:
CREATE TABLE Documents (Id VARCHAR); CREATE TABLE Ref_Shipping_Agents (Id VARCHAR)

Question: Which shipping agent shipped the most documents? List the shipping agent name and the number of documents.
SQL: SELECT Ref_Shipping_Agents.shipping_agent_name, COUNT(Documents.document_id) FROM Ref_Shipping_Agents JOIN Documents ON Documents.shipping_agent_code = Ref_Shipping_Agents.shipping_agent_code GROUP BY Ref_Shipping_Agents.shipping_agent_code ORDER BY COUNT(Documents.document_id) DESC LIMIT 1