The free Missing Metadata module adds a panel to the Control Panel of the Joomla Administration interface that lists any published articles that have empty metadescription or metakeys fields. Search engines (particularly Google) use the metadescription text as the summary text for site-listings displayed in search results. Any article that fails to include this metadata will suffer in its web presence and search engine ranking.
Chapter 13 of Beginning Joomla! shows how to make several different extensions. One of the tutorials takes the reader step-by-step through the creation of the Missing Metadata module. This module queries the Joomla article database and displays a small table showing any current articles with missing metadata as shown below.
Even more helpful, the listed items in the box are actually hyperlinks. Clicking on an article title will take you directly into the Article Editor where you can add the appropriate information for that item.
Once installed through the Template Manager, you will need to use the Module Manager to publish it and set the Position parameter to cpanel to make it appear in the Control Panel. Don't forget that when you select Module Manager from the menu, by default it displays all of the Site modules. You will need to click on the Administration link below the manager title to display the Administrator modules.
Note: If you find this extension useful, please vote for it on the Joomla Extensions Directory. To jump directly to the Missing Metadata module entry, click here. Thanks!
The Missing Metadata module in Joomla 1.0: