The main “concern” in respect to the Tool outputs is the current limitation.
You should make sure, that your circuitry will not draw more than the supplied 600 mA.
Exceeding this may cause permanent dame to the tool, and will as well cause to robot to go into Fault mode, powering down the arm.
Also pay attention to the Tool Digital Inputs section in the User Manual.
Logical high for TIx is min. 5,5 V, so you will probably need some transistor level shifting from the 5V digital output of the Arduino.