On the Laravel News site they've posted a tutorial showing you how to create custom Artisan commands making them available right along with the built-in framework commands.

I’ve written console commands in many different languages, including Node.js, Golang, PHP, and straight up bash. In my experience, the Symfony console component is one of the best-built console libraries in existence—in any language.

Laravel’s artisan command line interface (CLI) extends Symfony’s Console component, with some added conveniences and shortcuts. Follow along if you want to learn how to create some kick-butt custom commands for your Laravel applications.

The tutorial starts off with an overview of the current command structure and how a basic Symfony Console command is structured (code). They then get into the creation of their custom command - a "health check" command - by creating a new Laravel project and using the "make:command" command to build out the skeleton code for you. They add the command into the current config and show output of how it should now show in the "help" listing. From there the tutorial shows how to implement the HTTP checking with Goutte and how ot run it on a schedule, writing the result of the check to a log.