What Does it Mean?
The URLs have a Twitter Card description that is longer than the recommended 200 characters.
Twitter Card tags are a standard similar to Open Graph, but are only used for Twitter. These tags provide rich meta data about a page frequently used to created "cards" about a page when a link is shared Twitter. These cards may contain an image, description of the page, a site name, and other data that is much more visually appealing than just a simple link.
Twitter tags are <meta> tags with the name attribute set to a list of supported types with the prefix "twitter:". Here's an example of the "title" Twitter Card tag:
<meta name=”twitter:title" content=”Amazon.com: Online Shopping for Electronics, Apparel, Computers, Books, DVDs & more” />
There are five recommended Twitter card tags: "twitter:card", "twitter:site", "twitter:title", "twitter:description", and "twitter:image".
Why It's Important
Twitter descriptions longer than 200 characters run the risk of getting truncated, so anything past this point may not be visible in Twitter.
How To Fix
Look through the URLs with a Twitter Card description that is longer than the recommended 200 characters, and rewrite a description for each that is less than 200 characters.