The MetadataService offers a powerful tool with which developers can read and manipulate the schema of a CRM organization. The MetadataService allows you to programmatically perform the same operations that system customizers can perform in the user interface. This includes creating custom entities, creating and updating attributes, reading data about the various objects in the system, and manipulating multilingual capabilities. Developers should always thoroughly test their MetadataService code, because with this additional power comes more responsibility. The ability to delete a custom entity (and all its related data) in a single message is an example of MetadataService power.