It's shown in the link below. It's kind of crazy that they have this huge corporate announcement with 50 logos for something that under the hood seems sort of arbitrary and very fragile, and is probably very sensitive to things like exact word choice and punctuation. There will be effects like bots that say "please" and "thank you" to each other getting measurably better results.
https://google.github.io/A2A/#/documentation?id=multi-turn-c...