This is a great distinction that more dev teams need to think about.
Traditional SEO focuses on getting human eyeballs to a page through search engine indexing. It relies on keyword density, metadata, backlink profiles, and visual page layout. You can afford some fluff or fancy marketing language on an SEO page as long as Google ranks it.
Agent-readiness is completely different. AI agents don't care about page authority or pretty CSS. They need structured, deterministic inputs. When an agent reads a site or API, fluff actually hurts because it fills up context windows with junk tokens and increases the risk of hallucinations.
A few quick differences I've noticed when building for agents:
Are you looking at making your public web content readable by LLMs, or actually exposing tools/APIs for agents to execute actions? That usually dictates how far down the agent-readiness rabbit hole you need to go.