Maine Hosting

godthor

SEO Enforcer is a small plugin that works with WordPress SEO by Yoast (it’s required), that will truncate your title tag if it’s too long, same with your meta description tag. The length they are truncated at is a setting you can configure.
There is also an option to remove H1 tags from your content. Typically your theme will show the H1 tag for your post or page title already. Having more than one H1 tag is not recommended for SEO, so this will remove any it finds in your content and replace them with an H2 tag instead.
Plugin Requirements
<ul>
<li>WordPress SEO by Yoast v1.6.1+</li>
</ul>
Note: It may work on earlier versions of those plugins but it has not been tested.

SEO Enforcer

Ensures that your title tag and meta description tag aren't too long and truncates them if they are. Requires WordPress SEO by Yoast.

Farhad Sakhaei

ParsMizban

DediData

This plugin optimizes WordPress for better ranking in Google and other Search Engines 
* Add post excerpt as Meta Description 
Validated by: 
https://wpreadme.com/ 
https://wordpress.org/plugins/developers/readme-validator

Smart SEO

Smart SEO - WordPress Search Engine Optimization Tools

SEO Enforcer vs Smart SEO