This option allows you to choose a different description for search engines. It's recommanded to have a length between 200 and 300 characters, by default google displays 150 characters. For example :
- Use keywords in your text, avoid unattractive lists of keywords.
- Write a unique description for each page of your site.
- Vary the title tags of all your pages to avoid duplication.
- Describe the content of the page corresponding to the description, avoid repeating the title.