I’ve added field description to the table with MS_Description extended property. This appears fine in TDP’s navigation manager. When I go to the script tab and check the Extended Properties checkbox, I get each field’s MS_Description property line twice. The second sp_addextendedproperty line generates an error when the script runs; the property already exists at that point.
I’m running TDP 220.127.116.1126 against SQL Server 2008r2.