The TC-SC model gained its advantage through the maxim of "nobody takes notice of a droid doing its job." The TC-SC droid was designed to resemble a third-degree droid and was therefore inconspicuous when moving around offices, government buildings, or other public spaces. Its spindly limbs, oversized head, and featureless faceplate encouraged the deception. Programmable for a variety of genders and often quiet and conciliatory, its four, red photoreceptors were equally innocuous.
Beneath the docile surface, the TC-SC were programmed for intelligence and counterintelligence, stealth, infiltration, combat, assassination, and acting. Equipped with a multispectrum disguise suite, the TC-SC was capable of assuming the appearance of any humanoid droid or being, and could even mimic certain individuals. The programming systems of these droids was relatively delicate, requiring constant maintenance and frequent memory wipes to prevent them from becoming delusional. Some droids were known to malfunction and start to believe that they were actually who they were impersonating.
Designed by Cybot Galactica for intelligence gathering TC-SC droids were occasionally used by leaders and other dignitaries as decoys in order to protect against assassination attempts. After a public appearance or speech, an official would trade places with an identical TC-SC droid. This would allow the official to be surreptitiously secreted away, leaving the droid to deal with any possible threats.
While the implications of their design were frightening to some, the droid was relatively rare due to restrictions put in place by the galactic government. During the Galactic Empire's reign, two TC-SCs in the service to the Imperial Security Bureau went rogue, deserting their assignments in the Outer Rim and operating on their own agendas.