WordPress Plugin Tool Tip Helpers

What you’re looking for is called “pointers”, available since 3.3 and you’re right it lacks documentation.

It’s done with a little bit of JavaScript. You may look at this post to find useful information about pointers.

It uses native WP scripts and styles this way :

wp_enqueue_style( 'wp-pointer' );
wp_enqueue_script( 'wp-pointer' );

See also this answer to get inspiration ^^.