Missing Metadata adds a module in the Control Panel view of your Joomla Administrator. The module will remind you elements in your Joomla that have not metadata set. You will be able to add new keywords or description to "articles", "categories", and "menu buttons" right from your Control Panel.
Admin module for Joomla! shows in the main control panel menu lists, items and categories, in which there have been no metadata (description and / or keywords).