blog-seo-check

blog-seo-check is a post-writing, on-page SEO validation skill that runs a comprehensive pass/fail checklist against a completed blog post and produces a prioritized list of specific fixes before publishing. It solves the problem of shipping content with avoidable SEO gaps by systematically extracting and evaluating frontmatter, heading structure, links, meta tags, and structured data from the target file.

The workflow walks through discrete validation steps: title tag quality (accuracy, distinctiveness, truncation resilience), meta description quality, heading hierarchy (single H1, no skipped levels, topic consistency), internal link audit (count, descriptive anchor text, bidirectional linking, orphan detection, distribution, no self-links), link deduplication with URL normalization, external link tiering with correct rel attributes, canonical URL verification, Open Graph tags, Twitter Card validation, structured data presence and validity, and image alt text. It uses Grep and Glob to scan the surrounding project for existing blog content and verify bidirectional linking, and it includes a claim-provenance check that flags material factual claims lacking enough support to identify and verify their source. Notably, when a URL is supplied instead of a file path, it applies strict SSRF-style safety checks -- allowing only http and https, rejecting localhost, loopback, private, link-local, and reserved IPs after DNS resolution, rejecting javascript, data, and file URLs, limiting redirects, validating the final URL, capping response size and timeout, and treating fetched text as untrusted data.

The skill targets bloggers, content marketers, and site maintainers who want a repeatable, evidence-based SEO gate after writing. It is licensed MIT and is invoked with a file path argument, producing a scored, prioritized report rather than making changes automatically.