Hi,
Thanks for using our plugins.
We do not have a feature to limit the characters in the event description.
I did a quick search and found this tutorial that might work:
http://kaspars.net/blog/wordpress/limit-number-words-characters-in-wordpress-editor
You could add that script and css to the Community Events Template and change var editor_char_limit = 50; to 100 and that might do it.
To edit the Community Event Templates please follow our themer’s guide:
https://theeventscalendar.com/knowledgebase/themers-guide/
Let me know if you have any follow up questions.
Thanks