Description field visibility in Calendar items

We are leveraging the calendar function to manage a master planning calendar for a large organization.  Because most users are not Wrike licensees, we are using the 'external link' function.  This is working well with the exception being that the users can only see the milestone title, date & status - we would like to be able to have the option to let them see the milestone description as well, or another way to show them the milestone location, attendees required, etc.