We not so much measure it. I have seen checklists where people needed to say welcome in a certain way or use the customers name 2 times and similar things. My impression is that then calls become more robotic. The agents will learn to tick all the right boxes, but the call still will be very impersonal.
We have changed it to include more into coaching. And what we do is take one point per agents after listening in together with the agent. What we look at is the effort that the person puts into it. This will be very individual and depends from person to person.
Say if two agents do not use their name. One person you will notice is trying and sometimes still forget and the other won't even try. This will mean that the first person will get better 'points' then the second one.
And sometimes you see that one person tries very hard and might not succeed as fast as he and you would like, but really tries. This efford is what we reward, more then the result itself.
It all takes a bit more time, but we see positive results in our NPS.