Adding a little more than that might be a good idea If you want to check out my roleplay for a loose example to use, go right ahead. It's the first link in my signature. Go right ahead and add more or omit a part depending on what is relevant to your roleplay. For example, the roleplay you are wanting to start up talks about three different groups so adding more information about the groups and any other details would be a good idea. Make sure you post up rules or expectations that you are wanting in the roleplay. Another thing you might want to look at is at the
guide HeySeuss made to give you an idea that might work for you. His layout and what I have done for the OOC is a little more than what most people do for OOCs in Casual but as long as the presentation of information is good and the layout is easy to read, you should be fine with however much information you want to put up. The best thing to do is check out a few roleplays and see what GMs are doing for their OOC since each person has their own methods and you might find that some parts of one person might work better for you to use compared to another GM.
EDIT: Anyways, I'm heading to bed so feel free to pm me if you have any other questions at all and I'll get back to you in the morning.