Command arguments

How do i add those available commands in chat when u type a command that got arguments? Like vanilla

 

case "yourcommand":
if ($sender instanceof Player) {
if (!isset($args[0])) {
if (!$sender->hasPermission("yourcommand.command")) {
$sender->sendMessage($this->noperm);
return true;
} else {
$sender->sendMessage($this->prefix . "The args of ur command.");
return true;