Derek Ashauer

<p>TinyMCE has a built in feature to include a predefined list of links to select from. This plugin simply creates a list<br />
from your pages in WordPress. Create a link like usual in TinyMCE, but you now have a new drop down menu called “Link List”<br />
where all pages/links are already setup for you.</p>
<p>This currently only works for pages, not for posts.</p>


AWS Easy Page Link

Using the External Link List feature of TinyMCE, this makes it easy to create a link to another page on your website.

LuckyWP

<p>The plugin replaces plain-text editor for category, tag and custom taxonomy term description with the built-in WordPress WYSIWYG editor (TinyMCE).  This is allow you to insert images, use shortcodes, embed videos, audio and other content into term description.</p>
<h4>Features</h4>
<ul>
<li>Edit category and tag description with built-in WordPress WYSIWYG editor (TinyMCE).</li>
<li>Work in add and edit term forms.</li>
<li>Support WooCommerce category and tag description.</li>
<li>Support custom taxonomy term description.</li>
</ul>


LuckyWP Term Description Rich Text

Thanks to the author for the work. I already use on two sites

Very useful plugin

Replaces plain-text editor for category, tag and custom taxonomy term description with the built-in WordPress WYSIWYG editor (TinyMCE).

AWS Easy Page Link vs LuckyWP Term Description Rich Text