In a bag covered with dust, Jimmy keeps a set of tools "for breaking open a safe." The narrator says that "No finer tools could be found any place," and Jimmy looks at them "lovingly." We also learn that they are "made of a special material" and have been designed by Jimmy himself. They cost "nine hundred dollars" to be made, although later Jimmy says, in a letter written to an old friend, that one "couldn't buy them for a thousand dollars." When Jimmy uses the tools at the end of the story, they are described as "the shining strange tools."

From these descriptions, we can infer that Jimmy's tools are rather unique and special, and this is mostly because they have been designed specifically for a very particular task: safe-breaking. They seem to be very well designed, because they allow Jimmy to break open a safe very quickly. Jimmy is obviously very proud of the tools, and the fact that they are "shining" suggests that he takes care to look after them well.