If you need to extend the meteor tool or the command line, you'll need to create and publish your own meteor-tool package. Ronen's documentation is the best out there for this process:
http://practicalmeteor.com/using-meteor-publish-release-to-extend-the-meteor-command-line-tool/1
It's easy to get a meteor helloworld command working, but after that, I felt it was easier to just create a separate node app to test out commands. Which is how StarryNight came about. It's something of a staging ground and scratchpad for commands before trying to put them into a version of the meteor-tool.