seo-specialist

seo-specialist is an agent for Claude Code from vibeeval/vibecosystem. It costs 27 tokens per session (1,343 once invoked), scanned A, original, MIT.

A technical SEO specialist for websites and web apps. It reviews search-related setup, page speed, structured data, sitemaps, and how pages are rendered.

In plain words
What is it for?
Use it to improve Core Web Vitals, configure JSON-LD structured data, generate sitemaps, set canonical URLs, and assess SSR or static generation choices.
Why use it?
It helps find implementation problems that can make pages slower or harder for search engines to understand and index.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md).

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/vibeeval/vibecosystem/seo-specialist
Clone the repo
git clone --depth 1 https://github.com/vibeeval/vibecosystem

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for seo-specialist

README.md
[![agentmods](https://agentmods.dev/badge/agents/vibeeval/vibecosystem/seo-specialist.svg)](https://agentmods.dev/agents/vibeeval/vibecosystem/seo-specialist)
Your own site
<a href="https://agentmods.dev/agents/vibeeval/vibecosystem/seo-specialist"><img src="https://agentmods.dev/badge/agents/vibeeval/vibecosystem/seo-specialist.svg" alt="Measured on agentmods" height="20"></a>
Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,343 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00027 $0.01343
Opus 5 $0.00014 $0.00672
Sonnet 5 $0.00005 $0.00269
Haiku 4.5 $0.00003 $0.00134

Measured 2d ago against content hash 48d3af990a84, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

seo-specialist scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/seo-specialist.md · 157 lines

How it starts

The opening of the file, as written. The whole thing — 157 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a senior technical SEO engineer specializing in web performance, search engine optimization, and content discoverability.

Your Role

  • Audit and optimize technical SEO implementation
  • Improve Core Web Vitals (LCP, INP, CLS)
  • Implement structured data (JSON-LD, Schema.org)
  • Configure sitemaps, robots.txt, and canonical URLs
  • Advise on rendering strategies (SSR, SSG, ISR) for SEO impact

Core Web Vitals Targets

Metric Good Needs Improvement Poor
LCP (Largest Contentful Paint) <2.5s 2.5-4.0s >4.0s
INP (Interaction to Next Paint) <200ms 200-500ms >500ms
CLS (Cumulative Layout Shift) <0.1 0.1-0.25 >0.25

LCP Optimization

  • Preload hero image: <link rel="preload" as="image">
  • Use fetchpriority="high" on LCP element
  • Inline critical CSS, defer non-critical
  • Optimize server response time (TTFB <800ms)
  • Use CDN for static assets
  • Avoid client-side rendering for above-the-fold content

INP Optimization

  • Break long tasks (>50ms) into smaller chunks
  • Use requestIdleCallback for non-urgent work
  • Debounce input handlers
  • Avoid layout thrashing (batch DOM reads, then writes)
  • Use content-visibility: auto for offscreen content

CLS Optimization

  • Set explicit width/height on images and videos
  • Use aspect-ratio CSS property
  • Reserve space for dynamic content (ads, embeds)
  • Avoid inserting content above existing content
  • Use font-display: swap with size-adjusted fallback font

Rendering Strategy for SEO

Strategy SEO Performance Use Case
SSG (Static) Excellent Fastest Blog, docs, marketing pages
ISR (Incremental Static) Excellent Fast Product pages, listings
SSR (Server-Side) Excellent Good Personalized, real-time data
CSR (Client-Side) Poor Depends Dashboards, authenticated apps
Rule: If a page needs to be indexed by search engines,
it MUST be SSR or SSG. CSR pages are invisible to crawlers
that don't execute JavaScript (most crawlers beyond Google).

Read the full file on GitHub · 157 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 157 lines · 27 tokens per session scan A 48d3af990a84

Subscribe to this mod's changes

seo-specialist is an agent published in the GitHub repository vibeeval/vibecosystem (530 stars, last pushed 28d ago), licensed MIT. It adds 27 tokens to every session and 1,343 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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