While answering this, I realized that the "insufficient explanation" post notice had potential to be quite useful on sites like MO, Physics, Chem (possibly Math, Bio, CogSci, and the other science sites), but in its current state is quite useless.
The current "insufficient explanation" post notice is:
insufficient explanation - We're looking for long answers that provide some explanation and context. Don't just give a one-line answer: please explain why you're recommending it as a solution. Answers that don't explain anything will be deleted. See Good Subjective, Bad Subjective for more information.
It seems to be for recommendation/subjective questions. I actually don't see the need of it, since a good subjective question (refer Good Subjective, Bad Subjective and Q&A is hard, let's go shopping) explicitly asks for explanation. With that in mind, an answer which doesn't explain something can easily be commented on + deleted as Not An Answer. I don't see the need for a post notice here.
On Physics and Chem, we get plenty of answers which technically answer the question (and are thus not deletable), but are quite unsatisfying because they don't explain anything (for example this answer).
I propose a different wording. Maybe this could be a separate post notice, or it could replace the current one on sites that want it (or all sites):
insufficient explanation - We're looking for long answers that provide some explanation and context. Don't just give a one-line answer: please explain the reasons behind your answer.
This is no longer tailored specifically for subjective questions, and is now useful for placing a banner on one-liner answers.