This tool has slots for 9 stacks of cards when right clicked, if you keep this on your hotbar and interact with a device that can accept card there will be a small window showing what cards you have available to move into the device:
If you right click a device or cable with the network tool in hand it will give you a more detailed breakdown of the device and network and give you information such as how much power it is drawing or generating:
This tool will also allow you to make Facades transparent (right click with the tool in hand and use the toggle on the top right), this makes it easier to see where your cables are going and makes getting access to device or clabes much easier:
This only works if the tool is on your hotbar! Shift Right clicking any AE2 machines and cables will act like a wrench and make removing items much easier.