Search engines show the meta description under your page title in results. Without one they pick a snippet from the page themselves, and it is often not the one you would choose.
Why Joomla sites get it
Joomla only uses an article’s own Meta Description (the Publishing tab) when one is filled in. When it is blank, Joomla falls back to the meta description of the menu item that links to that article, and if there isn’t one, to the Site Meta Description in Global Configuration. So a site with a lot of articles usually ends up with most pages either carrying no description at all or all sharing the same site-wide one — which audit tools report as missing or duplicate descriptions.
Fix it by hand
- Open the article and go to the Publishing tab.
- Write a Meta Description of roughly 70–160 characters that says what the page is about.
- Save, and repeat for every article that has none.
Fix it with MetaGen
MetaGen writes a meta description whenever an article is saved without one, built from the title and intro text on your own server, with no external service. For articles that already exist, the Meta description missing row in MetaGen’s SEO tune-up panel shows how many have none, and Fix fills them all in at once. Every change is listed under Articles changed.
MetaGen is free for Joomla 5 and 6. See all the SEO warnings MetaGen checks.