ISMS Manual contents

I'm currently guiding an ISO27001 implementation project and aiding people in my team understanding what documentation needs to be done. A topic that comes regularly is the need for an ISMS Manual. I understand this not a mandatory document and to be honest it takes in lots of repeated (summary) information already in other documents of our ISMS. However, I understand some concepts written in this manual may be useful, such as explaining our Information Security organisational structure and the documental framework of the ISMS (what documents do we have, how do we split them into policies, procedures, work instructions, etc.). What do you recommend for documenting this type of info?