Clubberlang

Hi Folks, I am writing a professional reference for a collueage that I supervised that is applying for an MSW. We work for government in a call centre environment. The reference form asked me to speak to the persons intellectual abilities and they are excellent. I filled in the "additional info" block giving a few examples but after hitting submit I feel like I could offer more. I've heard that it's not uncommon for those supplying references to also write a letter to the school speaking to th person's ability. I think this might be a good idea. I am just curious what sort of things the admission team is looking for. Of course, I don't want to imbelish but at the same time I don't want to provide irrelavent info. Any advice here would be great. Thanks!