This extension gets four stars, for now.
Most of this accolade is for the idea and some of it is an encouragement to further development into a truly impartial algorithmic guide (insofar as this is possible).
I think the red-and-green categorisations are a little too black-and-white and likely to be controversial (because, increasingly, almost nobody among the general population reads "the news" without some acquired bias). Perhaps *White* should mean "so far as can be detected this site is trying to get it right" and *Amber* should mean "there is some doubt about the veracity of some items on this site" with, in both cases, a link to more detail. A third colour (Blue?) would be useful to indicate news aggregators with a legend along the lines of "This is a news aggregation site. Please check source articles on the originating sites".
Finally, it is disappointing that a particular print-and-online "news" publication recently had it's rating changed from "Red" to "Green" without changing its editorial stance in any way. To my mind "Red" was thoroughly deserved because the publication presents opinion as if it were fact and habitually spins news to such a degree that it winds up seeming to mean the opposite of the original facts. Others will disagree with me on that assessment but independently verifiable "facts" are "the news" which the reader should interpret whereas "opinion" is someone else's (often malicious and politically motivated) interpretation. When opinion is dressed up as the news it is *fake news*; when a fact is twisted it becomes a lie. If, under the colour scheme suggested above, the publication in question were to be marked "amber" (with straight-forward explanation) - No Red, No Green, - NewsGuard's rating would be less likely to seem biased, even to some of the One-Star Generals who, in this comment space, have denigrated this nascent attempt to differentiate information from disinformation.