Let’s start by outlining your ideal scenario, and then work backwards from there to figure out what options are available to you today that might help move things in the right direction.
Could you please walk me through what you’d like to see happen? I understand that you’d like users to see these guidelines before they begin interacting in chat — but is it mostly a matter of getting them to the topic or is there some other way you would like to present these guidelines? Is the first time users go into chat sufficient, or is there some other interaction / event that should result in users seeing / being directed to the guidelines? Understanding these specifics will help me figure out how we might support this or at least get you closer to this ideal state.