How does one use hook_boost_is_cacheable?

I created a page using hook_menu and can't get boost to cache it, so now I'm trying to use hook_boost_is_cacheable. My question is how do you actually use it? In my module, I have something like this:

function mymodule_boost_is_cacheable($path) {
	$path_arr = explode("/", $path);
	if ($path_arr[1] == "something") {
		return TRUE;
	}
}

Is that the correct way to use it? Thanks!