Your script is an applescript, not a shell script, so you can't execute it directly. I think it'd work to have the ossascript
command interpret it:
<array> <string>/usr/bin/osascript</string> <string>/Users/Shared/SCRIPT.sh</string> </array>
(& please use a more appropriate file extension than ".sh")
BTW, I'm pretty sure you want KeepAlive
set to <false/>
-- with it set to <true/>
, your script will be rerun continuously rather than just once.