Using Microsoft.Extensions.AI how to chain agents together?

[flintlouis]

This is a follow up question to #12098

I was wondering the same but using Extensions.AI
Let's say I have 3 models I want to use with different system instructions and different models and tools.
For example: model1 = "gpt-4o-mini", model2 = "gpt-4o" (file search based), model3 = ...

Pseudo code solution I can use:

var choice = Classifier.Classify(userPrompt)
switch (choice)
   case fileSearch:
           return await model2.GetResponseAsync(choice.Query)
    ...
    default:
           return model1

or what I do at the moment I use just one "gpt-4o" model with system instructions covering all three possibilities and add all tools.

Is there a better way to do this? For example something like: https://github.com/microsoft/semantic-kernel/blob/main/dotnet/samples/GettingStartedWithAgents/Step08_AgentAsKernelFunction.cs