Skip to main content
Glama
Sign In
Playwright Accessibility Testing MCP Server

Playwright Accessibility Testing MCP Server

by PashaBoiko
OverviewSchemaSourceRelated ServersDiscussionsAdmin
JavaScript
Local

a11y_scanUrl

Scan web pages for accessibility issues using WCAG 2.0/2.1 standards, identify violations, and capture screenshots with highlighted problems for compliance reporting.

Instructions

Run accessibility scan on a URL or specific element using Playwright + axe-core. Supports full page or targeted section scanning with optional screenshots. Uses comprehensive WCAG 2.0, 2.1 Level A/AA and best-practice rules by default.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "url": "<url>"
    },
    "name": "a11y_scanUrl"
  }
}

Input Schema

NameRequiredDescriptionDefault
urlYesURL to scan for accessibility issues
selectorNoCSS selector to scan only a specific section/element (e.g., 'header', '.main-content', '#navigation')
waitForSelectorNoCSS selector to wait for before scanning (useful for dynamic content)
captureScreenshotNoCapture screenshot of the scanned area with violations highlighted
timeoutNoNavigation timeout in milliseconds

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv1.0.0

TDQS

A3.6/5.0
Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It discloses some behavioral traits: it uses 'comprehensive WCAG 2.0, 2.1 Level A/AA and best-practice rules by default,' which indicates the scanning standards. However, it does not mention performance aspects (e.g., rate limits), authentication needs, or what happens if scanning fails. The description adds context but does not fully compensate for the lack of annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is appropriately sized with two sentences that efficiently convey key information: the core functionality and the scanning standards. It is front-loaded with the main purpose. However, the second sentence could be slightly more concise, and there is minor redundancy (e.g., 'comprehensive' might be implied).

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complexity (accessibility scanning tool with 5 parameters), no annotations, and no output schema, the description is moderately complete. It covers the purpose, technology, and standards but lacks details on output format, error handling, or integration context. It should do more to compensate for the missing structured data, especially for a tool with multiple parameters and no output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all parameters thoroughly. The description adds minimal value beyond the schema by mentioning 'optional screenshots' (related to captureScreenshot) and 'supports full page or targeted section scanning' (related to selector), but it does not provide additional syntax, format, or usage details. Baseline 3 is appropriate as the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: 'Run accessibility scan on a URL or specific element using Playwright + axe-core.' It specifies the verb ('scan'), resource ('URL or specific element'), technology stack ('Playwright + axe-core'), and scope ('full page or targeted section'). It distinguishes from the sibling tool 'a11y_scanInteractiveByText' by focusing on URL-based scanning rather than interactive text-based scanning.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage context by mentioning 'full page or targeted section scanning' and 'optional screenshots,' but it does not explicitly state when to use this tool versus the sibling 'a11y_scanInteractiveByText' or other alternatives. It provides some guidance on capabilities (e.g., supports dynamic content via waitForSelector) but lacks explicit when/when-not instructions or named alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server

Other Tools