If you have to supply the word "area" to get the answer for the "physical size" of a country, then it's rather restrictive. It's doing just key-word spotting and not really "understanding" what a human person is asking. I may well have typed in "area singapore" without having to phrase it like a question, because those are the words it needs.

Correct me if I'm wrong but I think most average speakers of English will comprehend the questions What is the physical size of Singapore? or How big is Singapore? At the very least, a human person will be able to correct me and prompt me with a question like: Do you mean the area of Singapore?