That’s solved by MCP though. You can update your MCP’s servers schema dynamically without ever having to touch the app itself but the app will be aware of the new schema.
I'm not saying that the schema can't change from time to time, I'm saying that having any fixed schema at request time is not an ideal user experience because it may not be clear what is supported and what is not supported. From first principles, it's much better if the app schema can be created dynamically at request time so we can guarantee that we can fully serve the user's request exactly as they asked it.
