IBM Websphere Business Modeler.
WBM allows you to do document several things of the roles inside a process.
Look all the stuff you can put inside a role.
Qualifications, Costs, Availability, Documentation... you can have a color for this role. You can really document what is this role about.
Blueworks Live "Participants".
More than roles inside a process, they have participants.
It is useful only for setting the roles on the "swimline".
I don't know where to document that on Blueworks Live.
If I'm wrong please let me know and post a comment on this page.
Update: I noticed that on the glossary of Blueworks Live you can add a little description of the "participant". But you can not document much more.