Agent Goff was a local Droid spy under a Mil disguise. During a mission on the Ruins of Iron Star, Goff was captured by the Mils and they've dismantled the agent. Colonel Alloy dispatched Glitch into finding the remaining parts of Goff and assemble him so that he could provide information about Dr. Exavolt's whereabouts.
After Glitch managed to find the parts and assemble them on a Mil Constructor, Agent Goff told him that Exavolt was being held on the Mil City Tower. He provided Glitch with an upgraded Arm Servo and ran away from the scene, never to be seen or heard from again.
Agent Goff is a Droid spy but has the appearance of a Mil Grunt (exactly from those Grunts who wield a Level 2 Rivet Gun), possibly working under disguise in order to infiltrate and acquire information from the Milbots. He is a great friend and ally to Agent Shhh, and that is proven when he told Glitch that Agent Shhh is a true man that "fights for a cause, in the trenches fighting hard, dishing out pain and destruction".
In terms of behavior, Goff seems to be quite energetic during his speech to Glitch. However, he is also quite the coward. Although he provided the information that Glitch needed to know to rescue Dr. Exavolt, he refused to go with him because he "wouldn't sign for no suicide mission".