à ton avis ?
This is a standalone sentence. What do you think it means? Does it mean "What do you think?" It's like snapping at someone when they ask an obvious question.
This is from minute 36 of this video:
yup, it works fine with captain obviouses. but also you can ask for opinions with that too :)
Yes, it means "what do you think".
In can be used either in a real question "Quel est le chemin le plus court à ton avis ?".
Or it is also often used to tell the other person that he is asking a stupid question with an obvious answer. This is the case in the video.
Un avis = an opinion/an evaluation, a litteral translation would be "what's your opinion ?".
Avis is for example the word used on consumer websites where you leave comments about a restaurant or an hotel.