Approximate word count of plain text extracted from HTML
Whether all required structural HTML elements are present
Whether placeholder/template markers were detected in the output
Computed read-time based on actual word count (words / 250, min 1)
Claimed read-time extracted from the article (0 if not found)
Whether the html lang attribute matches the expected language
Whether the dir attribute is correctly set for RTL languages
Whether meta tags (title, og:title, twitter:title) are synchronized
Whether keywords contain at least some localized terms for non-English articles
Quality metrics collected during content validation