Misconception: GEO can be solved by adding schema, llms.txt, or another machine-readable file. That sounds technical, but it becomes fragile if the page itself has no visible body, no stable URL, or no sitemap entry.
Verified signal: Google's guidance for AI features still points back to Search fundamentals. Pages need to be crawlable, indexable, eligible for previews, and technically healthy. Hermes also recorded schema.org 30.0 signals such as GS1 and Digital Product Passport examples, but those do not prove that AI Search directly consumes every schema field.
Action checklist: use schema as a consistency layer, not as a replacement layer. First confirm HTTP 200, visible title, visible body, canonical, robots, sitemap, and snippet eligibility. Then make Article JSON-LD match the visible content. Do not place facts only inside structured data if a human reader cannot also see them.
19LAB test result: the independent pages for 19LAB and yijiu.me now expose titles, body text, and Article JSON-LD. The next check is whether the visible article and JSON-LD say the same thing.
Reusable principle: schema can help AI understand a page, but it cannot read for the AI. Visible body text comes first; structured data confirms it.