Fabio M. Giacomini

This plugin adds a new field in every post, where you can write a text that will be inserted in the related meta tag, located in the head section.
The main options page of the plugin, provides you with a default text area, where you can insert a default description that will appear in case the field in post page is empty.

Single Post Meta Description

The easiest way to add in every post page a different meta description tag, located in html head.

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

Single Post Meta Description vs Smart SEO