Nope, that's not going to give you the ability to actually test for the presence of a DSL signal. It just makes sure that you don't interrupt one on the line.
You are going to need to spend the money (and lots of it) to purchase such an animal, the basic equivalent of a laptop equipped with a DSL modem. This service isn't simple, like caller ID which many butt-sets are able to test.
Sorry for the bad news. The good thing is; DSL is either there or it is not. There are no gray areas, so testing devices really aren't necessary.