The log info should be displayed in the gateway each time the script is triggered but this doesn't happen. I even commented the rest of script out so that just these two lines remain, but still haven't seen anything when I trigger the script. Anything else in the script works.
Vision logs go to the local vision client log as @Transistor said. If you want those logs to go to the gateway logs, you'll need to create a message handler to do it. Send what you want to a gateway message handler, and log it from there.