From the official website of Star Wars The Old Republic comes a full dossier explaining one class of character you find in the game, Imperial Agent.
Imperial Agent is a special operation whose mission is infiltration, espionage and covert missions to capture insurgents or find traitors among the ranks of the empire. Your best companions are the sniper rifle technology and gadgets that make their jobs easier.
From Star Wars Latino forums you can read the full translation of the original article in English.