Yes you should (when feasible).
You should be able to take a fresh machine and build your project with as few steps as possible. For me, it's:
- Install IDE (e.g. Visual Studio)
- Install VCS (e.g. SVN)
- Checkout
- Build
Anything more has to have very good justification.
Here's an example: I have a project that uses Yahoo's YUI compressor to minify JS and CSS. The YUI .jar files go in source control into a tools directory alongside the project. The Java runtime however, does not--that has become a prereq for the project much like the IDE. Considering how popular JRE is, it seems like a reasonable requirement.