Malamud keeps things as sparse and direct as possible; we don't see a lot of flowery phrases and run-on sentences here. He sticks to the point, he uses easy-to-understand words, and he never wants the reader to get lost in the phrasing and risk missing the meaning behind it all.
"The Magic Barrel" is has a pretty dense plot, and Malamud's aerates this density with a very precise choice of words. For example, he describes Salzman as "a skeleton with haunted eyes" (116). That's only five words and yet it says a ton about Salzman's character, demeanor and state of mind at that moment.