The value of the "Chenillette" as an armoured fighting vehicle was limited. In French service, the "Modèle 31" carried no armament, although some later vehicles had attachment points for a removable AA-machine-gun to be fitted — but this had to be operated from outside the vehicle in an awkward crouched position due to its low height. For the crew to use personal weapons through the hatches while sitting inside the hull was highly impractical. Consideration had been given to arming it with a machine-gun, but the "Direction de l'Infanterie" feared that if such a weapon were mounted, the UE would be misused as a light tank rather than being dedicated to its correct tactical resupply role. Likewise the armour protection was minimal. The vertical plates had a thickness of nine millimetres, the other plates, all riveted, were six millimetres thick, just enough to stop normal rifle bullets and shell fragments.