# Core Web Vitals Scorer MCP for AI Agents MCP

> Core Web Vitals Scorer evaluates three critical web performance metrics—LCP, INP, and CLS—against industry standards. It gives you a composite health score and estimates how these scores might impact your site's search ranking. Stop guessing about page speed; get actionable data that tells you exactly where to improve.

## Overview
- **Category:** analytics
- **Price:** Free
- **Tags:** lcp, inp, cls, web-vitals, google-seo, performance

## Description

Websites need to load fast and feel responsive. But simply knowing the speed isn't enough; you need context. This MCP connects web performance metrics (LCP, INP, CLS) against established Google standards. It doesn't just give you a number; it analyzes that data to give you a composite health score and estimates your potential SEO impact. Instead of manually checking different dashboards for every metric, you feed the raw numbers into this MCP. Your agent processes them instantly, telling you if they fall in the 'Good,' 'Needs Improvement,' or 'Poor' range, and pinpointing exactly which area needs work. Accessing these kinds of detailed analytics used to mean juggling multiple expensive monitoring tools. Now, with Vinkius as your central catalog, you connect this MCP once and get expert-level performance scoring right where you're already working.

## Prompt Examples

**Prompt:** 
```
Analyze this performance data: LCP 2.8s, INP 450ms, CLS 0.15.
```

**Response:** 
```
**Performance Analysis Report**

Based on the inputs:
*   **Overall Health Score:** 68.0/100 (Medium)
*   **Estimated Ranking Impact:** Moderate Negative

The analysis highlights that while CLS is acceptable, the LCP and INP scores are pushing your site into a 'Needs Improvement' zone, which will likely limit visibility on search results pages.
```

**Prompt:** 
```
What are the current thresholds for CLS?
```

**Response:** 
```
**Core Web Vitals Thresholds (2024)**

The scoring boundaries change, but here is the general guide:
*   **Good:** Value below 0.1
*   **Needs Improvement:** Value between 0.1 and 0.25
*   **Poor:** Value above 0.25

Knowing these thresholds helps your development team target improvements precisely.
```

**Prompt:** 
```
Can you give me the status of an INP of 350ms?
```

**Response:** 
```
**Metric Status Check: Interaction to Next Paint (INP)**

**Result:** Needs Improvement

*   **Your Value:** 350ms
*   **Threshold Range:** Ideal is below 200ms.
*   **Actionable Insight:** This score indicates noticeable jank or lag during user interactions. Focus optimization efforts on JavaScript execution and main thread blocking.
```

## Capabilities

### Assess single metric status
Determine if a specific metric value (like LCP or CLS) meets defined quality thresholds.

### Run a full performance analysis
Evaluate all three major metrics—LCP, INP, and CLS—at once to generate an overall site health score.

### Reference scoring boundaries
Look up the exact acceptable ranges for each Core Web Vitals metric based on industry best practices.

## Use Cases

### Auditing a slow-loading landing page
A marketer runs into poor user retention on a key landing page. They feed the LCP, INP, and CLS data to the MCP; it returns an overall health score of 45/100 and flags that the high CLS is causing significant bounce rate issues.

### Pre-launch performance sign-off
A developer finishes a major redesign. They use `analyze_performance_suite` to test the full suite, ensuring all metrics are 'Good' before handing it over for final SEO review.

### Comparing against best practices
An SEO team member needs proof points for a client meeting. They use `get_threshold_reference` to show the precise, current scoring boundaries for LCP and INP, backed by industry standards.

## Benefits

- Stop guessing about page speed. Use `analyze_performance_suite` to generate a single, composite health score that tells you where your site actually stands.
- Get immediate status checks on specific metrics by calling `classify_metric_value`, instantly knowing if an LCP of 2.5 seconds is acceptable or not.
- Avoid rework cycles by using `get_threshold_reference` to confirm the exact numerical boundaries for CLS and INP before your team starts coding.
- The tool estimates potential SEO ranking impact, giving you a direct line between technical fixes and search visibility improvements.
- It standardizes complex performance data, allowing your agent to process metrics across different frameworks or platforms with consistent results.

## How It Works

The bottom line is you get an immediate, comprehensive performance report without having to consult multiple external auditing tools.

1. You feed your raw web performance data—the numbers for LCP, INP, and CLS—to this MCP via your AI client.
2. The system analyzes these inputs against standardized industry thresholds to calculate a composite health score.
3. Your agent returns clear status classifications (Good/Poor) and an estimate of the potential SEO ranking impact.

## Frequently Asked Questions

**How does the Core Web Vitals Scorer help with general site speed issues?**
It goes deeper than simple load times. The Core Web Vitals Scorer measures how your page *feels* to the user—how fast elements paint (LCP) and how smoothly interactions feel (INP). This helps you fix the real, frustrating slowdowns.

**Is this tool better than just checking Google PageSpeed Insights?**
It provides more context. While other tools give scores, the Core Web Vitals Scorer analyzes those metrics against established thresholds and gives you a composite health score plus an estimated SEO impact, making the data actionable.

**What does 'Needs Improvement' mean for my website?**
It means your page is functional but has noticeable flaws—like occasional jankiness or slow loading of large images. Fixing these small issues can significantly boost user satisfaction and search rankings.

**Can I use the Core Web Vitals Scorer for non-website platforms?**
No, this MCP is specifically designed to evaluate standard web performance metrics (LCP, INP, CLS) that apply only to web pages and digital content.

**What if I don't know which metric is the biggest problem?**
Run the `analyze_performance_suite`. It runs all three metrics through the system and gives you a single, prioritized overall health score, telling you exactly where to focus your development efforts first.