We have community accepted rules both on phil.SE and SE in general that regard how homework questions should be handled. Here we voted overwhelmingly to agree that homework questions that do not show any effort in an attempted solution should be closed (put on hold until the necessary edits have been made). Here is a meta.SE post where the community agreed with basically the same idea, that people should not be doing homework for users and that the user should show that they have made an effort to solve the problem themselves.
The question Is this argument about “either or” valid or invalid? is an example of a homework question which does not meet any of the criteria outlined for being an acceptable question, and further more it received three answers which just amount the answerer's doing the person's homework for them. This question and these answers, according to the community guidelines which have been outlined in the posts linked above, should not exist in their current state. This site is not a place for people to cheat on their homework, it is a violation of academic integrity for someone to do so and it is wrong for the answerers to be aiding in a violation of academic integrity. The situation can easily be fixed by the questioner showing their attempts at answering the question, and that is exactly the reason we have the rules in the first place. My comment on the question pointing out our rules for homework was deleted and I have no idea why.
So, all of that being said, should we add a "Homework" tag?
With that tag, we can correctly identify homework questions which would allow us to know when the question does not show an adequate amount of effort at an attempted answer, and we can know when answers are also not complying with the guidelines of "don't do people's homework for them," which will help with appropriately adjudicating the situation.
I genuinely believe that doing people's homework for them, besides being dishonest, is detrimental to their over all academic journey; doing someone's homework for them does not help them learn, even if it's with the intent of "hey, this will show them how to solve the problem". Given that we often get questions that are clearly just copy-pasted from the homework page, this tag would serve the purpose of clearly delimiting when and where the community should take action to improve the questions and prevent answerers from cheating someone's homework for them.