The documentation in the tooltip informs the user that they are able to use the Groovy GDK but doesn't make it clear to the user on which machine the Groovy code will execute.

teilo mentioned with the following snippet that it wouldn't work because it would run on the master:

node {
    if (System.getProperty("os.name") == 'Linux') {
        sh 'echo "hi"'
    }
}