The tag is present in Lintian version 2.104.328. That is the most recent version we know about.
The short description should be kept short (50 characters or so) so that it may be accommodated by most debconf interfaces. Keeping it short also helps translators, as usually translations tend to end up being longer than the original.
Please refer to Debian Developer's Reference section 188.8.131.52 for details.