What is an Agenda in GTD?
It is the set of next actions that you need to do with a person or group of people. It works like a context.
An Agenda is a list of Next Actions related to a person or group. They are a great tool to reliably save all the things you need to discuss with people or teams with whom you regularly meet, so that the next time you have the opportunity to speak with them, you can keep track of all pending issues, without forgetting anything.