On each landing page you are able to configure the meta tags manually. Click "edit" at the top of the page and scroll down until you reach the "meta tags".
In the meta tags settings you can configure the content for the title, description, keywords and abstract tags of the page. Click the link "Browse available tokens" to find a list of tokens which when used, will dynamically populate the tag with the specified content.
Additional advanced settings are available which for instance enables you to tell search engines how to crawl and index the page.
Note: If a description is not defined for a page, a description tag will not be added to the page.