This means that Bing cannot show a description about the page as it is not being allowed by the website's robots.txt file.
The site owner has blocked Bing from crawling the page and hence we are not able to show you a description. If you know the site owners, let them know that ‘your website robots.txt is blocking Bing crawler and Bing cannot create a useful description in search results’.
If there is no specific set of directives for the Bingbot user agent, then Bingbot honours the default set of directives defined with the wildcard user agent. So, remove the statement disallowing access for the wildcard user agent or add Bingbot specific statement.
If you want to allow Bingbot to crawl the whole website, include the following snippet in your robots.txt file.
You can perform any of the below options for preventing Bing from crawling and displaying your page in the search results.
Remove the page from your site– The most natural way for a URL to be removed from our index is to delete it from your site so that the URL returns a 404 (Not Found) or 410 (Gone) HTTP status. After re-crawling the page and establishing that it has been removed permanently from your site, we will remove the page from our search results. Implement a ‘noindex’ meta tag in the page– If you need to remove a URL from the Bing search results that you cannot or don't want to delete from your site, you can add a robots meta tag to your HTML source. Bing honours meta robots tags, and adding <meta name="robots" content="noindex"> to your page source will ensure that the page will disappear from the index once it has been re-crawled and re-processed. Remove the URL using the Block URL tool– If you are in a hurry to get a URL out of the index and don’t want to wait for the natural recrawl process, you can block a URL using the Block URLs tool inside Bing webmaster tools. This should remove the URL from the index within roughly 24 hours. Note that URL blocks are temporary and expire every 90 days, but this should give you time to either remove the page from your site or add a NOINDEX meta tag to the page.