A robotic surgical system comprising: a surgical tool a robotic manipulator having a tool holder to which the surgical tool can be releasably coupled, the robotic manipulator being arranged to manipulate the surgical tool to cause the surgical tool to move; and a processor for controlling the robotic manipulator to control movement of the surgical tool; wherein the surgical tool comprises: a probe having a proximal end and a distal end; a surgical end effector disposed adjacent the distal end of the probe; an interface disposed adjacent the proximal end of the probe, the interface releasably coupleable with the tool holder; and circuitry mounted on the probe, the circuitry defining a signal for transmission to the processor to indicate compatibility of the tool with the system; wherein the signal comprises unique identification data and an encrypted verification data string calculated from the unique identification data according to an algorithm; wherein the processor is configured to: receive the signal from the tool when coupled to the tool holder; manipulate the unique identification data with the algorithm to produce confirmation data; compare the confirmation data to the encrypted verification data string to verify compatibility of the tool with the robotic surgical system; and enable the robotic surgical system to manipulate the tool if the confirmation data matches the encrypted verification data string. a surgical tool a robotic manipulator having a tool holder to which the surgical tool can be releasably coupled, the robotic manipulator being arranged to manipulate the surgical tool to cause the surgical tool to move; and a processor for controlling the robotic manipulator to control movement of the surgical tool; wherein the surgical tool comprises: a probe having a proximal end and a distal end; a surgical end effector disposed adjacent the distal end of the probe; an interface disposed adjacent the proximal end of the probe, the interface releasably coupleable with the tool holder; and circuitry mounted on the probe, the circuitry defining a signal for transmission to the processor to indicate compatibility of the tool with the system; wherein the signal comprises unique identification data and an encrypted verification data string calculated from the unique identification data according to an algorithm; a probe having a proximal end and a distal end; a surgical end effector disposed adjacent the distal end of the probe; an interface disposed adjacent the proximal end of the probe, the interface releasably coupleable with the tool holder; and circuitry mounted on the probe, the circuitry defining a signal for transmission to the processor to indicate compatibility of the tool with the system; wherein the signal comprises unique identification data and an encrypted verification data string calculated from the unique identification data according to an algorithm; wherein the processor is configured to: receive the signal from the tool when coupled to the tool holder; manipulate the unique identification data with the algorithm to produce confirmation data; compare the confirmation data to the encrypted verification data string to verify compatibility of the tool with the robotic surgical system; and enable the robotic surgical system to manipulate the tool if the confirmation data matches the encrypted verification data string. receive the signal from the tool when coupled to the tool holder; manipulate the unique identification data with the algorithm to produce confirmation data; compare the confirmation data to the encrypted verification data string to verify compatibility of the tool with the robotic surgical system; and enable the robotic surgical system to manipulate the tool if the confirmation data matches the encrypted verification data string.