Trying to get the custom addon tutorial 2-Point tool to start

Hey guys, 

i've been trying my luck to understand the basics about how custom tools or usercontrols can be added. 

The tutorial found here:

is very well documented, but for some reason i can't get the added tool to start. It's just unresponsive and clicking on it won't actually fire the OnStartState Method/Event.


Does anyone have an idea what i'm missing here? Thanks in advance.