Laravel - Artisan Console - Input Descriptions

You may assign descriptions to input arguments and options by separating the argument name from the description using a colon. If you need a little extra room to define your command, feel free to spread the definition across multiple lines:

     * The name and signature of the console command.
     * @var string
    protected $signature = 'mail:send
                            {user : The ID of the user}
                            { --queue= : Whether the job should be queued}';