In working with Microsoft Support I received this answer below, which is definitely not ideal, as it only really describes the views. I will update if I get a better response from them.
It looks like the database schema details is internal only and not available to public. Only public documentation is here:
http://msdn.microsoft.com/en-us/library/ee943755(v=vs.110).aspx
Documentation on DB scripts is here:
http://blogs.msdn.com/b/carlos/archive/2013/01/10/workflow-foundation-sql-scripts.aspx