Surgical tools having a two degree-of-freedom wrist (70), wrist articulation by linked tension members (218, 220, 222, 224), mechanisms (372, 390) for transmitting torque through an angle, and minimally invasive surgical tools incorporating these features are disclosed. An elongate intermediate wrist member (80) is pivotally coupled with a distal end of an instrument shaft (74) so as to rotate about a first axis transverse to the shaft, and an end effector body (72) is pivotally coupled with the intermediate member so as to rotate about a second axis that is transverse to the first axis. Linked tension members (218, 220, 222, 224) interact with attachment features (180, 182, 184, 186) to articulate the wrist. A torque-transmitting mechanism (372, 390) includes a coupling member (384, 394), coupling pins (398, 400), a drive shaft (392), and a driven shaft (396). The drive shaft is coupled with the driven shaft so as to control the relative orientations of the drive shaft, the coupling member, and the driven shaft.
