So, this would seem to be fairly easy to test empirically. Get a reasonably object measurement of the quality of writing, and use it on something where you know if it's true: 1) court testimony which we know (from outside evidence) is either true or not true 2) scientific papers which we know to have been reproducible, or not 3) stock pundits predictions about the future of some company or other, which we know with h…
The way I interpret this is that it refers to claims that build on each other to come to a conclusion. So the way to test for truth is to somehow test each claim and the conclusion, which could vary in difficulty based on the kind of claims being made.
As this essay exemplifies, it is difficult to test for truth if you make broad claims that are so imprecise that they can't be verified or don't tell you anything interesting when verified using reasonable assumptions.