Checking structured data involves more than confirming that schema markup exists on a Shopify page. A Shopify schema markup tool should examine the markup’s structure, required properties, data accuracy, and whether different schema types are implemented appropriately. Identifying missing fields, formatting problems, and validation issues can help store owners maintain cleaner structured data and give search engines clearer information about products and other important page content.

Read Blog: https://medium.com/@jsonschemaapp/what-should-a-shopify-schema-markup-tool-actually-check-e385a8add00f