Schema Editor
The Schema section gives you a basic overview of the schema being edited.
The Version field is provided so that you can have a form of version control. This means that client apps built against an earlier version of the Schema will know if the middle-tier's Schema is newer and therefore shouldn't interact with it.
The Custom Attributes field allows you to specify a String that can be accessed at design time but also through Data Abstract classes. You can use this for anything you want, for example if you be used to specify the level of permission need for a user to be able to access this schema.
The Scripts area, which is available below the Schema section, is where you can put Business Rules aimed at the Schema level, for instance actions that are triggered when a user logins in to the schema or after a change delta has been applied.
The script editor providers syntax highlighting and a convenient shortcut for adding context appropriate methods to the editor window, which allows you to just focus on the body of the JavaScript method. Also available is a handy button that will validate your code for basic correctness.
Information about Business Rules Scripting and the available API is available in the Technologies section.