The problem here is that your answeryour answer does not seem to rest on any evidence beyond your own intuition as a native English speaker. The trouble with intuition is that it does not really generate knowledge as such: there is no way for third parties to verify that your intuition is correct, or to adjudicate between native speakers who claim to have different intuitions.
In particular, you claim that constant polarity tags indicate "verification of something that is apparent" whereas the Grammarpedia article cited in another answeranother answer claims that "constant polarity tags are used to express surprise". So, verification or surprise? Which is right? Or can they be used for both? How am I to tell?
(As far as I can tell from a very quick search, the scholarly literature agrees with Grammarpedia and not with you: for example Huddleston and Pullum write, "constant polarity tags ... don't ask for confirmation, but suggest an attitude such as surprise, disbelief, disapproval or the like". But maybe a more thorough search would find evidence for your theory too.)
If this site is to be more than a venue in which people express their opinions, then people need to back up their answers with evidence, in the form of scholarly citations, corpus searches, results of experiments, and so on.