Max Kenworth is an agent with SOCOM.
I do not know if the people working directly for the U.S. Special Operations Command as Kenworth does are actually referred to as agents but considering the type of work that Kenworth is called upon to perform, the term definitely applies.
We are told upon our initial meeting in the first recorded adventure that this "former Delta Force officer, now retired from the Army ... worked for the J3 (Director of Operations at SOCOM) and headed up the highly classified program at headquarters, having todo with nuclear-weapons planning and counter-proliferation of weapons of mass destruction". Exactly how long Kenworth has been a civilian employed by that military organization is not stated but it is quite clear it has been a while and Kenworth is on a close, friendly relationship with the J3. This sometimes means enjoying a game of chess now and then when not involved out in the field or, less desirable for Kenworth, at one of the far too many international conferences "stuffed with supposed intellectuals without any practical experience and with an idealistic view of the world, as they sat in an air-conditioned room and took breaks every hour to shove pastries in their faces and wash them down with bad coffee." That last was from Kenworth's viewpoint and his attitude is mirrored often when bureaucrats and diplomats and, even worse, politicians are involved. Kenworth, to his dismay, is a frequent attendee to these confabs because though he does not like them, he is considered "one of the foremost authorities on nuclear weapons and often called upon for advice and expertise".
Kenworth is described as having "short, jet-black hair" and being "built like a freight liner". Though he had left the military some years before, he has maintained his physical shape religiously and could easily pass any drill thrown at him.