Described herein include various embodiments of a tool assembly for performing endoscopic surgery that can be used manually and/or with a robotic surgical system. The tool assembly can include a shaft assembly that extends from a housing of the tool assembly. A distal end of the shaft can include an end effector that includes a clamp arm pivotally coupled to a blade for cutting and/or sealing tissue. Pivoting of the clamp arm between the open and closed configurations can be caused by movement of a yoke that is slidably disposed within the housing of the tool assembly. For example, the yoke can be caused to move by one or more outputs (e.g., a manual output, a rotary output, and/or a linear mechanical output). Furthermore, some tool assembly embodiments can include a biasing system that biases the yoke such that the clamp arm is in the open configuration. In some embodiments, the tool assembly can be configured for tissue spread dissection using the clamp arm and blade.