Here's the short answer. A custom Claude Code skill (a SKILL.md file) teaches Claude how to write: your voice, your banned phrases, your structure rules. An SEO MCP server gives Claude data and actions it doesn't have on its own, like keyword research with search volumes, the pages that rank today, publishing to your CMS and Search Console data. If you already get briefs from an SEO team and have a strong voice guide, a skill alone will do. If you also need research, publishing and tracking, add an MCP server. The strongest setup is both.

Below you'll find a side-by-side comparison, a SKILL.md you can copy, the ready-made SEO skills people install, what to look for in an SEO MCP server, and a prompt sequence that runs the whole thing from keyword to published post.

Custom Skill vs SEO MCP Server at a Glance

Quick definition first. MCP stands for Model Context Protocol. In practice, it's a way to connect Claude Code to outside tools and data, so Claude can call a keyword tool or publish to your site instead of just generating text.

Is Claude Code good at SEO? It writes well when you give it rules and data. Without rules, you get generic prose. Without data, it guesses which keywords matter and what Google already rewards. The rest of this page is about giving it both.

What a Custom Claude Code Skill Does for Blog Posts

A skill is a SKILL.md file that holds your voice guide, your business context and your writing rules. When you ask Claude Code for a blog post, it follows that file instead of falling back on its default style. Every post gets the same tone, the same heading structure and the same rules about sources.

This is a genuinely good choice in plenty of cases. If an SEO team or an SEO tool already hands you content briefs with the target keyword, the search intent and an outline, the hard research is done. What's left is turning that brief into a post that reads like your company wrote it, and that's exactly what a skill is good at. It also costs nothing beyond Claude Code itself.

The other big win is consistency. Without a skill, each session starts fresh and you end up re-explaining your audience and pet peeves every time. With one, you explain once.

Example SKILL.md for SEO Blog Posts

Here's a starting outline you can copy and fill in. Keep it short enough that you'd actually maintain it. Check Anthropic's Claude Code documentation for where skill files live in your setup.

---
name: seo-blog-post
description: Use when writing or editing a blog post for our website. Applies our voice, banned phrases, structure and sourcing rules.
---
SEO blog post writer
Purpose and audience

We are [company], we sell [product] to [audience].
Readers are [role], usually busy, often comparing options.
Goal of every post: answer the search fully, then point to a sensible next step.

Voice

Tone: friendly, direct, a little dry. Never salesy.
Person: “we” for the company, “you” for the reader.
Sentences: mostly short. One idea per paragraph.
On-brand lines (examples):

“Here’s the short version.”
“If you only do one thing, do this.”


Off-brand: exclamation marks, rhetorical questions as openers.

Banned phrases

Hype words: game-changer, revolutionary, cutting-edge, seamless, unlock, leverage
Filler openers: “In today’s fast-paced world”, “Let’s dive in”, “It’s worth noting”
Cliches: “at the end of the day”, “take it to the next level”

Structure rules

Answer the search in the first paragraph.
One H1 (the title). Descriptive H2s that say what the section contains.
Paragraphs of 1 to 3 sentences.
Use a table when comparing options on the same criteria.
Title tag: max [N] characters. Meta description: max [N] characters.

Sourcing rules

Cite a source for every statistic, price or date.
Never invent figures, studies, quotes or customer stories.
If no source exists, make the point without a number.

Output format


Markdown with front matter:
title: …
slug: …
meta_description: …

Then the post body, starting with the answer.

The banned phrases list is the section people underrate. It’s the fastest way to make AI drafts stop sounding like AI drafts.

What a Skill Alone Can’t Give You

A skill is instructions. It isn’t data, and it can’t take actions outside the conversation. Here’s what that means in practice:

• Search volume and difficulty. Without them, Claude guesses keywords. You might write a great post for a phrase nobody searches, or one dominated by sites you can’t realistically outrank.
• The pages that rank today. Without seeing them, the post can’t match the search intent Google is rewarding or cover what those pages miss. You’re writing blind against competitors you haven’t read.
• A publishing step. With no connection to WordPress, Webflow or Wix, you copy and paste by hand, fix formatting, add the meta description and set the slug yourself. Fine for one post a month, tedious for ten.
• Search Console clicks. Without them, you can’t see which posts bring traffic and which ones need a rewrite.
• Indexing status. Without it, you don’t know whether Google picked up the post at all.

None of this is a flaw in skills. It’s just a different job. If someone else covers these steps for you, a skill is all you need.

Ready-Made SEO Skills You Can Install

Is there a universal SEO skill for Claude Code? There are several installable SEO skills, each built around a different job. The ones that come up most:

• Claude SEO: an open-source plugin on GitHub, also presented on claude-seo.md. It describes itself as an SEO analysis toolkit for Claude Code focused on site audits across technical SEO, content and related areas.
• Claude SEO Skill (claudeseoskill.com): presents itself as a skill that crawls your site and produces SEO, GEO and AEO audit reports.
• InfraNodus SEO skill: presented as combining search intent analysis with topical clustering to find content gaps.

These suit people who want audits or analysis inside Claude Code: finding technical issues, checking structured data, spotting topics you haven’t covered. They’re a different thing from a custom writing skill, and you can run one alongside your own SKILL.md.

Before you rely on any of them for blog posts specifically, check three things: does it pull real keyword volumes, can it publish to your CMS, and does it read your Search Console data? If the answer is no, you’ll still need another piece for those steps.

What an SEO MCP Server Adds

An MCP server exposes tools that Claude Code can call during a conversation. For SEO, that typically means keyword research, briefs built from the pages that rank, publishing, scheduling and Search Console reports. You ask in plain language (“find keywords I could rank for”), and Claude calls the right tool and works with the result.

Not all SEO MCP servers do the same things. When you’re comparing them, look for:

• Keyword data with volumes, not just keyword ideas. Ideas without volumes put you back to guessing.
• Analysis of the pages that rank for a keyword, ideally turned into a brief you can hand to your skill.
• The CMS it publishes to. Confirm your platform is supported before you build a workflow around it.
• Search Console access, so you can see clicks per page without leaving Claude Code.
• Auth method: OAuth sign-in or an API key. OAuth is easier to set up; an API key is handy for scripts and shared setups.
• Remote or local. A remote server is a URL you connect to. A local one runs on your machine, which some teams prefer for control.
• Cost, and what you get for it. Some charge for data, some for articles, some for both.

Using Both: Skill for Voice, MCP Server for Research and Publishing

This is the setup that covers everything. The two pieces don’t overlap, so they fit together without changes. You keep your existing skill exactly as it is. The MCP server handles the parts the skill can’t.

1. Research (MCP server): find keywords with volumes your site can realistically win.
2. Brief (MCP server): build a brief from the pages that rank for the chosen keyword.
3. Draft (skill): Claude writes the post from the brief, following your voice and structure rules.
4. Review (you): read it, fix what’s off, check sources.
5. Publish (MCP server): push it live or schedule it in your CMS.
6. Report (MCP server): a few weeks later, check clicks and rewrite what underperforms.

Research comes in, your voice gets applied, you stay in charge of the final call, and the post ends up on your site without copy-pasting.

Setting Up an SEO MCP Server in Claude Code: Balzac Example

To make this concrete, here’s how it works with Balzac, the AI SEO agent behind this site. Balzac runs a remote MCP server at https://mcp.hirebalzac.ai. You sign in with OAuth or with a bz_ API key. If you’d rather run it locally, there’s also a local option that runs with npx balzac-mcp.

In Claude Code, add it with:

claude mcp add —transport http balzac https://mcp.hirebalzac.ai

Then run /mcp inside Claude Code to sign in.

The tools it exposes include:

• generate_keywords: keyword ideas for your site
• create_briefing: a brief for a chosen keyword
• rewrite_article: rework an existing post
• publish_article and schedule_article: push a post live now or later
• search_console_overview: your Search Console data
• create_competitor: track a rival site

It publishes to WordPress, Webflow, Wix, GoHighLevel or any site through a webhook. Every account gets 3 free articles with no card, and paid plans start at $79 a month for about 30 articles, with a 30-day money-back guarantee. Full setup steps are on Balzac’s MCP page at hirebalzac.ai/mcp.

Example Prompt Sequence in Claude Code

Here’s what a full run looks like with your blog skill and an SEO MCP server connected. The prompts are plain language; Claude picks the tool.

1. ”Find keyword ideas for my site that a small site could realistically rank for.”
   Triggers generate_keywords.
2. ”Let’s go with the third one. Create a briefing for it.”
   Triggers create_briefing, which plans the post from the pages that rank today.
3. ”Write the post from that briefing using our blog post skill.”
   Your SKILL.md takes over: voice, structure, sourcing rules, output format.
4. ”Check the draft against the skill’s banned phrases and structure rules, and fix anything that breaks them.”
   Skill again. Then read it yourself before moving on.
5. ”Looks good. Schedule it for Tuesday morning.” (or “Publish it now.”)
   Triggers schedule_article or publish_article.
6. A few weeks later: “Show me the Search Console overview and rewrite the posts that get impressions but few clicks.”
   Triggers search_console_overview, then rewrite_article.

Optional: “Track competitor.com as a competitor.” triggers create_competitor if you want to keep an eye on rival sites.

Which Setup to Choose

• You already have briefs and a voice guide, publish now and then, and don’t mind pasting into your CMS: a custom skill. Next step: copy the SKILL.md outline above, fill in your voice and banned phrases, and test it on your next brief.
• You mainly want site audits or content gap analysis inside Claude Code: an installable SEO skill like Claude SEO, Claude SEO Skill or the InfraNodus SEO skill. Next step: read each one’s install instructions and run it on your site.
• You need keyword research, publishing and tracking without adding more tools: an SEO MCP server. Next step: run through the checklist above and confirm it supports your CMS and Search Console before connecting it.
• You want consistent voice plus research and publishing: both. Next step: keep your skill as is, add an MCP server with one command, and run the six-prompt sequence on a single keyword to see the whole loop before you scale up.

Whichever path you pick, start with one post. You’ll learn more from reviewing one real draft than from tuning the setup in the abstract.

Sources

• I Got Claude Code to Build My Entire SEO Strategy