This was also my understanding. The last time I looked at writing good commit messages (a similar form), the standard was to finish the sentence: "This commit will...", e.g. "This commit will fix buffalo.spam" from "Fix buffalo.spam".
I like this a lot.
This commit/PR will _______.
Is it the objective or what is actually done?
There could be a recommended set of "codelabels" for which there are also gh issue/pr labels.