Schema markup has long been treated as a tool for winning rich results — star ratings, images, FAQ snippets in the search results. But its real value runs deeper: schema markup for AI search is core infrastructure that helps search engines and large language models understand what a website actually is, by explicitly declaring the entities on a site and the relationships between them.
Why Knowledge Graphs Are the Real Target
The starting point is the knowledge graph, which stores entities as nodes and their relationships as edges. That structure lets machines move beyond keyword matching into semantic understanding. Take a university business school as an example: rather than reading it as a string of text, a well-built knowledge graph recognizes it as a single entity — an organization that offers courses and employs people who teach them.
JSON-LD as an On-Ramp, Not a Rich-Result Hack
JSON-LD schema functions as an on-ramp for this understanding. Instead of waiting for a bot to infer entities and relationships from body copy, JSON-LD declares them directly. The point isn't to stuff in FAQ schema for rich-result clicks — a web page is really a vehicle carrying nodes and edges into the graph.
A Three-Layer Framework for Entity Gaps
To operationalize this, one framework compares three layers: custom schema markup (in one case, more than 60 custom entities built on top of Schema.org's 23 standard types for a specific industry vertical), vector embeddings of site content, and an AI agent that analyzes semantic proximity between the two. Comparing these layers surfaces entity gaps — the missing pieces a content strategy should fill. The goal isn't implementing every possible entity; it's first defining what a complete "ideal entity model" looks like, then prioritizing the gaps by business value.
The Evidence Is Mixed — Measure Accordingly
Research on schema's actual effect is split: one 2025 study found no impact on LLM visibility, while other research suggested LLMs don't read on-page schema at all. Countering that, Microsoft Bing has confirmed Copilot uses schema markup to understand content. The practical takeaway is to separate using JSON-LD to help machines understand a site from treating JSON-LD as a shortcut to citations, and to measure success beyond rich results — tracking prompts, brand sentiment, and AI mentions, then tying those back to actual conversions and lead quality.
For teams building out an AI-search content and structured-data strategy, Best Partner's services can help translate this into a prioritized roadmap, and our related piece on topical authority in ChatGPT category share digs further into the same shift.