I was looking for guidelines, but the best I could find is this. Is there a better statement somewhere?
That was hard enough to find. Perhaps an entry could be put in the help to make it easier to find.
I thought this was a settled issue, but the comments to the answer I linked suggest otherwise. Do we have a consensus? If we are not a homework help site, I would think that we would want to discourage complete answers.
In any event, I think a clear statement in help would give us something to point to as a reason.
addendum: five years later
Is there any change that makes it easier to find the policy on answering homework-like questions? (N.B. answers, not questions)? Five years after submitting this question I still can't find a policy statement. If there is a statement it should be more prominent. We shouldn't be surprised that we see complete answers even from folk who have more than 100 rep. points.
addendum #2
In the help/FAQ section "How do I write a good answer?" please add a paragraph on answering homework-like questions.
addendum #3
"Don't post complete answers to homework-like questions." Is there some reason we don't post that in a location prominent enough that newcomers see it? I seem to be seeing more and more complete answers. Today there's a question with two complete answers. We're becoming an online answer key.