It looks similar to the Gauss Gun from half life and also to the Gauss Gun from half life 2 on the jeep. The tool gun is held by the player with two hands similar to a revolver probably to keep it stable as using the tool gun on the wrong thing by accident, can have not good results! The tool gun is actually the same as the revolver but the ammo part has been replaced with some kind of wire/electricity part that maybe makes power like a battery. The screen on the tool gun also features scrolling text which could be a very useful feature if you dont know what tool you are using. The tool gun beam is like a lightning arc that comes out of the end and can apply a tool from a long range to whatever it hits and wherever it hits. Its appearance consists of a screen put on top of a revolver handle with some electric parts stuck on it as well, and a barrel that the tool gun beam comes out of.

The Tool Gun is a weapon in Garrys Mod used to create all contraptions builds devices cars planes trucks, tanks you name it. Notice the switch on the handle to the right that is not yet used and may be added in a future update.

Gauss gun half life