Lets use a concrete example… You want to book a flight from Denver to Seattle. You tell GPT, “I want to book a flight from Denver to Seattle”. It selects the “BookFlight” plugin. That plugin doesn’t have enough information to go on so it needs to ask additional questions. It asks “when do you want to leave?” You don’t want to direct the response to that at a different plugin so you you first need to remember you’re in the middle of booking a flight and should direct future request to the BookFlight plugin. When do you stop forwarding messages to that plugin? You need to know when the conversation has ended so issue #1.
Lets say the user then says, during the middle of booking a flight, “oh I’m also going to need a car.” That’s not something the BookFlight plugin is going to understand how to do and is what we call an interruption. You need a mechanism for first detecting interruptions and then deferring them to be handled later. Modern chat bot frameworks support this but its non-trivial.
These are all solvable issues but I don’t see the current approaches to plugins as solving them. They’re missing so many features that I don’t know where to start with my critique.