It is almost impossible to check the condition while the driveshaft is installed in the car. If installed and you can feel play it is up to a dangerious condition. Remove the drive shaft from the car and check the joints for binding, roughness or play. If any is felt replace the joint. After installing a new joint it should be free not stiff. If stiff tap on the driveshaft yokes to allow the ears to spread removing the bind from the joints.