I find that the short description was being written to the iCal feed / ics file with carriage returns in it, which isn't allowed in the iCal spec. It looks like the code in
components/com_matukio/views/ics/tmpl/default.php
attempts to remove carriage returns but it doesn't quite work. This causes only the first line of the short description to be displayed in the iCal feed reading tools I tried (MS Outlook, JEvents, and DPCalendar). I changed the syntax of the str_replace line and it seems to work fine now. Carriage returns follow through to JEvents via iCal since they are now replaced with the literal string "\n", which is allowed in the iCal spec. Also, I suggest including the Matukio event URL with the description so the user has a way to get back to the event and make a booking, see more details, etc. As well, html is not allowed in iCal descriptions so I added some code to do some basic conversion of HTML in the Matukio short description to ASCII. The HTML to ASCII code is based on the code at http://www.hashbangcode.com/blog/convert-html-ascii-php. It's very basic but it works and could be expanded if you want more html tags supported.The result is now I get Matukio events showing up in my main JEvents calendar with my other events, the complete short description is displayed, and a link is included in the iCal description so users can get back to the Matukio event details page.
My changes start around line 51 of
components/com_matukio/views/ics/tmpl/default.php
attached to this posting and the conversion function is at the end.