I wonder if it's just our egos talking, telling us that for something to have value within this technical sphere it has to be complex and 'hard won'?

I see this agent stuff as a pretty basic agreement wrapped up in the vernacular of a protocol, i.e. "we'll put this stuff in the 'role' prop on our JSON", and then everyone else knows where to look for it. It's not especially important what we decide, as long as we create shared expectations.

I used to think protocols and RFCs and other products of standards bodies were the juicy 'big boy table' of tech, but then I realised: ok, it's not so complex–and perhaps doesn't itch my engineering itch–, but SOMEONE needs to take responsibility for deciding the protocol, otherwise it's just a bunch of randoms making up interfaces 1:1 with other parties and no useful tooling emerging for a long time. Best to beat it to the punch and just figure out a 'good enough' approach so we can all get on and make cool stuff.

Addendum: I will say, however, that the AI space has a particularly unhealthy attraction to naming, coining, forming myriad acronyms and otherwise confusing what should be a very simple thing by wrapping it up in a whitepaper and saying LOOK MA LOOK!