As I said in the comments I believe that the limits of "no effort" are subjective and it's very difficult (and maybe even counterproductive) to try to give a one-size-fits-all solution.
The reason why is because you need to understand the background of the question and the user asking it, in order to judge. Personally, when I'm judging a contribution to see if it "shows no effort" the next question I ask myself is "why do I think that the OP didn't put that effort when writing the question?".
It could be for many different reasons that the questions wasn't elaborated or researched more. Some people may not be aware of the etiquette in most sites of trying to google something before asking about it (remember that "Let me Google that for you" thing?) Some OPs may be lazy about writing a good question that lets other help them better (and make them want to help the OP, by showing genuine interest, effort and appreciation for other's time and effort). Some OPs might be new to the site and/or unaware of our etiquette of trying to help people learn instead of just doing somebody else's homework.
It could be that the answer to the OP's question is easily answerable using a textbook. It could be that they failed to explain that they already checked one and/or why what they are reading there doesn't help them understand the answer. Maybe there are other problems with the question, like it is too broad or unclear, or not well targeted enough.
Should we be more patient, instead, with people who believe they can learn a language by deciphering translations?
We should be willing to encourage good practices by explaining them to newcomers and help bring up to speed new users so they understand what "quality contributions" are. We should also be willing to assume "good faith" with other user's contributions until proven otherwise.
Since we may know little about the OP, let's assume that they might be somebody who needs more understanding of the rules of the stack (maybe even life in general). Consider that you can take other "punitive" actions before you vote to close, like commenting or downvoting (it would be good that you explain that you are downvoting because you perceive the contribution to have low effort for XYZ reasons, and that you will revert the downvote once that the issues get addressed).
Thus said, even if we remind people that we are not a substitute for their teachers, textbooks and similar resources (we are more like a classmate willing to help them) there will be lots of people not willing to put enough effort in their contributions. If you feel kind of being "taken advantage" by trying to answer a given question or feel that is difficult to help a user because they didn't make it easy for us to help them (or for us to want to help them), just vote to close.
After all yours in only one of five votes to close. Other community members need to assess if the question deserves to be closed for that (or other related) reason(s). It could happen that there is a good reason to close the question because the OP didn't invest enough effort on it.