I posted this answer very recently and someone has downvoted it as well as one of my other older posts. Will this be considered as serial downvoting, and can I flag for mods?
@DatBoi To answer your question : in my opinion two votes is too little and it's not clear that it's the same person/motivation because the quantity is that low. Regarding your answer : keep a stricter rule for yourself and don't even answer at all if the question doesn't have context. It's ok to provide a milder version of the hint as a comment, but look to use comments to combine answering the question with asking OP to improve it according to site rules (or just generally).
@DatBoi You can flag and ask moderators to delete the question. The other option is that I downvote and ask people here to delete it (we need three people) but I will do this only if you are fine with it.