Apple does not now provide information about calibrating batteries, so that may give you a hint about the importance of that operation for Apple.
You can certainly try a "calibration" if you like.
If you have an idea for how you want to do that, then try it out.
Now, keep in mind that you already don't quite trust what Coconut Battery might be telling you. The BEST way to tell about battery life is to use your laptop on battery, and watch how long your battery actually lasts on a charge.
Just in case you want to try out MY idea about battery calibration, this is how I would proceed. I do this once or twice a year, at the most.
Use your laptop on battery only, letting the battery run completely down, until it eventually goes to sleep (and you can't continue without plugging in to charge)
Plug in. Let it charge to full charge (the LED on the charger will change from orange to green) You can continue to use your MBPro while it is charging.
At full charge, shut your MBPro off. Unplug the charger. Let it sit, power off, fully charged for a few minutes, maybe an hour or two.
Use it as you normally would.
I think one of the reasons that Apple no longer offers tips about battery calibration, is that it is, on the face of it, rough treatment of a battery. It can push a "problem" battery over the edge.
I had a 2008 MacBook with a battery that was not charging completely. I tried a calibration, and the battery suddenly swelled to the point of bursting - big surprise!