Hi,
The onResourceChange field must be exactly the *.capella value. It expects a file extension. See EASE/Scripts - Eclipsepedia.
# onResourceChange : *.capella
Then in the script code argv[0] gets you the name of the resource that triggered the execution of the script. You should then retrieve the model from this information and do whatever you want (test it to only apply the script on the desired model for example).
Regards,
Arnaud