From The TimeSplitters Wiki

The electrotool fires a continuous narrow beam of electricity over long distances. Due to its electric nature, it naturaly does more damage against robotic charicters and slightly less against biological characters. The electrotool is generaly a poor choice for multiplayr matches, as it takes some time to defeat any enemies, usualy long enough for the target to deal much damage to you. In story mode however it becomes much more effective on the robot factory level, being able to disable robots for a short time and to destroy the power nodules.