Our "low quality post" algorithm certainly seems to pick up on pure-code answers, however on occasion people (like the asker of that question) explicitly request a code snippet that performs a certain function. If this is the case should any additional info be added if an answerer only posts code?
If we should add a description, what should we say? A high level description? An explanation of why you're using X function or Y operators? This is in part problematic because it may not be immediately clear why an answered picked the exact statements they did unless there's something obviously wrong/right with it.