AD groups are imported into the aspnet_Roles table in your SQL Server database using a stored procedure called aspnet_Roles_CreateRole.
The aspnet_Roles table has a column for Description, but I'm unsure if that is actually imported from AD when aspnet_Roles_CreateRole runs - open your db and check that column.
Importing other group properties is not supported out of the box with the default ActiveDirectory/Windows providers. You would have to build your own provider, I think.
I imported AD users and groups into my episerver. It seems, I can import only group names but not other properties of the group like Description, Notes....
Pls let me know if there any way to import group properties into episerver.