The tags on this question confused me:
In the comics Did Thanos "kill" just sentient beings or all creatures with the snap?
It's tagged as marvel-cinematic-universe, even though the question is explicitly about the comics and not the films. Is that tag misleading?
It really depends on a case by case basis but, in my opinion, it comes down to: does this contain major spoilers for the work? If it does then adding/leaving the tag on the question really wouldn't do much harm but can save others from seeing potential spoilers. If the question has no spoilers and pretty much uses it as a reference for the main question then it isn't really needed.
In this particular example the question is sort of in the middle of the two options, it contains spoilers in a roundabout way but also only uses it as inspiration for the question. I did originally leave the tags because of the spoilers but on a re-read it doesn't necessarily give any spoilers away except indirectly. That and the fact that the tags were causing confusion1 is why I have now removed the marvel-cinematic-universe and avengers-infinity-war tags.
1. You, yourself, was confused by this and several users have left comments that only apply to the MCU so it wasn't an isolated case.
