Haris Zulfiqar

WordPress tooltip plugins lets you add tooltips to plain text and links on your post and pages.
It offers a tinyMCE shortcode GUI which will guide you through the entire process of a tooltip.
This plugin uses jQuery tipTip authored by Drew Wilson http://code.drewwilson.com/entry/tiptip-jquery-plugin.
You can also add tooltips manually by following the pattern below:
<pre><code>[tooltip content="This will show in a tooltip" url="This will make tooltip a link"]Hover over me for tooltip[/tooltip]
</code></pre>
Url is optional. If URL is added, it will render a link otherwise it will be a plain text.

WordPress Tooltip

WordPress tooltip lets you add tooltips to content on your posts and pages.

Simon Blackbourn

When new features are introduced into WordPress, various helpful pointers (tooltips) maybe shown to users on the admin screens. This simple plugin disables them for all users. No options, no configuration, just install and activate.

Disable Pointers

Disable the pointers (tooltips) shown on WordPress admin screens

WordPress Tooltip vs Disable Pointers