Earlier quoted context omitted.
Yeah you can call the language a tool, since most languages can get the same job done but some do certain jobs better.
JavaScript has consistently beaten out any other language as the client-side language of choice in both my personal and professional projects. Clearly, it deserves the top spot.
To use the normal house-building analogy, I would say that the Tools are obviously saws, drills, etc. Things that you use on every house you build but that are not part of the house itself. These represent notepad, visual studio, git, etc.
The Materials are wood, nails, etc. Things that make up the house and are not removed when the builder leaves. These represent the actual code (ie, lines/libraries of javascript) you build with your tools.
e: So it's like saying the #1 carpenter's tool is wood.