Re: For what it's worth...
It is cloud agnostic in the sense that you can use one tool (and perhaps more importantly one language) to control more than one cloud service.
It isn't agnostic in the sense that you can write one resource block that will do something on more than one cloud. I'm fairly certain that wouldn't even be a good idea. You'd either have so much bloat for each resource (to cover each cloud's differences) or you'd have a seriously limited tool by design (to only capture each cloud's similarities).
I've seen shops write modules that created resources in different clouds. It worked but they weren't pretty.