Robotic surgical tools, systems, and methods for preparing for, and performing robotic surgery include a memory (126) mounted on the tool (54). The memory (126) can perform a number of functions when the tool (54) is loaded on the tool manipulator (58). First, the memory can provide a signal verifying that the tool (54) is compatible with that particular robotic system. Secondly, the tool memory (126) may identify the tool-type to the robotic system so that the robotic system can reconfigure its programming. Thirdly, the memory (126) of the tool (54) may indicate tool specific information, including measured calibration offsets indicating misalignment of the tool drive system, tool life data, or the like. This information may be stored in a read only memory (ROM), or in a nonvolatile memory which can be written to only a single time. The invention further provides improved engagement structures for coupling robotic surgical tools with manipulator structures.