What changed in answer engine, generative engine and agent optimization, checked against sources. Each briefing links its evidence and labels how well supported each claim is.
MCP Server Cards are now Final as an optional discovery extension, Cloudflare changed how Block treats mixed-use crawlers, and Sierra and Meta proposed a Personal Agent Protocol.
An arXiv study of 468,037 ChatGPT citations reports that retrieval explains about 32% of citation variation against 2.8% for page properties. A small vendor study agrees on the sources.
Google announced more inline links in AI Overviews and AI Mode and now documents a Search generative AI control. Two small studies show AI assistants send little traffic.