Yandex.Webmaster has new tools that will help you quickly find pages with duplicate title and description tags.
Information about them can be found under
Indexing → Titles and Descriptions. The section displays examples of pages with a large number of non-unique title and description.
A summary of the number of duplicate tags can also be found in a dedicated section in the Summary. The information is updated after the robot visits the page.
A special alert has appeared in the Diagnostics section : if a large number of identical titles or descriptions are found on the site, a warning letter will be sent to the mail. To receive alerts, you need to subscribe to the “Possible problems” Diagnostics.
Note that the innovation was presented today by Mikhail Slivinsky at the tenth Yandex Webmaster conference.