To qualify as a chess summer camp, it should have at least half a day on chess exclusively. Otherwise your child will not get enough exposure and will not gain much chess experience.
The second thing you should check is the teacher. Sometimes the (famous) name on the flyer may not be the one who will teach the camp. S/he organizes the camp but hires someone else to teach. Or s/he just lends his/her name to the organizer for marketing purpose. You have to ask.
As selecting a coach, you should select a teacher with rating high enough to help your child. Unrated teachers are only good for total beginners. You should do some research on camp history and the teacher's teaching methodology. If you can talk to previous campers, they would provide you great insight on how the camp is run. The more information, the better.
It never hurts that you know the teacher before.