The “reset Password form” is sometimes confusing for newcomers. Here a easy way to add tool tips to the password field and the reset password button.

**
* Add Text to the login footer, Tooltips for reset password - uses Tippy for the tooltip
**/
add_action( 'login_footer', 'myplugin_custom_footer' );
function myplugin_custom_footer() {
    ?>
    <p style="text-align:center;">
           Some explanation text for the login form</p>

<script src="https://unpkg.com/popper.js@1"></script>
<script src="https://unpkg.com/tippy.js@5"></script>
<script>
	   tippy('#resetpassform #pass1', {
       content: " tooltip text for the password field",
	   placement: 'right',
       });
   
	   tippy('#resetpassform #wp-submit', {
       content: " tooltip text for the reset password button",
	   placement: 'right',
       });
	 </script>  
	 
    <?php
}

I inserted this function in a custom plugin.

References:

• https://codex.wordpress.org/Customizing_the_Login_Form
• https://www.cssigniter.com/how-to-add-custom-fields-to-the-wordpress-registration-form/
• https://atomiks.github.io/tippyjs/