- comfortable reach (double the arm legth)  
- strength of squeeze (high as possible, but variable)  
- size of hand (double the size of human hand)  
- weight (low as possible without sacrificing other goals, preferably below 2000g)  
- flexural strength (high as possible, without sacrificing other goals)  
- comfort (as comfortable as possible)  
- range of motion (as close to the ROM of a human forearm and hand)  
- intuitiveness (as understandable and usable as possible)