It doesn't really matter what it is as there are many equally good implementations, but whoever sets up the framework first and cements usage is likely to guarantee dominance for the foreseeable future. Probably into AGI and post.
Model Context Protocol seems good enough to me.
The idea behind smolagents is better.
I agree the idea seems much better - and I think it's what a lot of big-shops are doing internally too. An earlier article [1] showed that internally, gemini has a python sandbox it uses to call other google services.
I'm guessing the main limitation is that it's harder to orchestrate, especially on clients.