You are pretty much out of luck. The development of this tool seems to have stopped around 2010. I think there is some word document in the source download under the "Resources\Docs" folder, but admittedly, it's really out-of-date. The feeling I get is that
the material there was made during the development of CHESS around 2008 or 2009 and never updated. I have a PM from mormayo (Developer in this project) semi-confirming this.
Another avenue for you to look at is here,
It's a set of notes made for a concurrency class in a university by the CHESS team.
Now, if you are interested in studying the tool (CHESS) and making some PROPER documentation about it, please PM me. I've been whacking my head around for the past few weeks and could use help!