On the old eventlist it was possible to add a description text that showed above the eventlist.
This was done by putting the text you wanted in the language variable 'COM_MATUKIO_DETAILS_PAGE_FOR_EVENTS'.

This is no longer possible in the new modern eventlist.

I would like to have this option again. Right now I've coded this my self by copying the code for this from the default.php to the modern.php.
It's this code:

		<?php $navioben1 = array();

		if ($this->art == 0)

		{

				$headline = array(JTEXT::_('COM_MATUKIO__DESC'), JTEXT::_('COM_MATUKIO_DETAILS_PAGE_FOR_EVENTS'));

		}

		MatukioHelperUtilsEvents:rintHeading($headline[0], $headline[1]);?>

I put this after the component heading.
This is a easy solution, but it only works for people who know where to find and edit the language strings.
You could also think about using the category descriptions for this. The only thing that lacks is a general description when "All categories" is chosen. Maybe that can be done as a template or a setting.