There is a possibility to make pull request for that matter.
We have a "template" that is displayed in the textarea for new issues:
https://github.com/joomla/jissues/blob/master/src/App/Tracker/tpl/new-issue-template.md
And those "help messages" are taken from a language file:
https://github.com/joomla/jissues/blob/master/src/App/Tracker/g11n/en-GB/en-GB.Tracker.po

@brianteeman do you have any suggestions for the text there? Thanks.

I would probably not bother at all with that first instruction

Please note, that this is not meant as a "must do", but more like an experimental way - if it does not work for any reason, we have to find some better alternative - open for any suggestions

Look at github and what it states at the top when you create a new issue. Very liitle

Looking at joomlacode (http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemAdd&tracker_id=8103)
there is

Report security issues to security@joomla.org, please do not use the public tracker for security issues. Please review http://docs.joomla.org/Priority to determine what priority level to use. Please review http://developer.joomla.org/coding-standards.html for code style information.

I thought we might add the possibility to write some sort of "intro" - if it's not needed, we'll scratch it.

In the joomlacode view it is ABOVE the ticket and acts as an intro to the entire ticket
In the jissues view it is BELOW the title and looks like it is something to read after you have started the ticket

So it's more about the placement..
Perhaps we should create an "intro text" field for a project that is always displayed, additional to those fancy hideable (un)helpful texts describing the fields ?

I think this has been superseded by #242