Systems, devices, and methods designed to make it easier to couple end effectors to surgical instruments are provided. A variety of features are disclosed, which can be used independently or in conjunction with each other. The resulting benefits include enhanced visualization, more secure coupling, easier communication that coupling has occurred, self-clocking components with respect to each other, and more component modularity. In one exemplary embodiment, an end effector assembly having an end effector and an attachment arm includes a terminal end surface of the attachment arm having a three-dimensional configuration such that a portion of the end surface extends further away from a set location than another portion of the end surface extends from the location. In another exemplary embodiment, end effector assemblies include chambers having curved configurations that assist in self-clocking the assemblies with respect to surgical devices. Other features, devices, systems, and methods are also provided.
