 <p>Why not put the custom tool property back in to be able to rapidly test it? then take it out when you are happy?</p> <p>another option is to write a .tt file that consumes/includes that .tt to operate as your <a href="http://en.wikipedia.org/wiki/Read%E2%80%93eval%E2%80%93print_loop" rel="nofollow">REPL</a> harness</p>