Playwright Accessibility Testing MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It describes key behaviors: 'Automatically discovers and tests interactive elements' and 'Uses comprehensive WCAG 2.0, 2.1 Level A/AA and best-practice rules by default.' However, it lacks details on permissions, rate limits, error handling, or what the test results look like (especially since there's no output schema).

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

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

The description is front-loaded with the main purpose, followed by usage examples and default rules. Every sentence adds value: the first defines the tool, the second explains automation, the third gives usage context, and the fourth specifies standards. No wasted words.

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

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

Given the tool's complexity (6 parameters, no annotations, no output schema), the description is incomplete. It covers the 'what' and 'when' well but lacks details on behavioral traits (e.g., what happens during testing, error scenarios) and output format. Without an output schema, the description should ideally hint at return values.

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

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

Schema description coverage is 67%, and the description adds meaningful context beyond the schema. It explains the core concept: 'finding them using visible text/labels' and 'automatically discovers and tests interactive elements,' which clarifies the purpose of containerText and autoDiscover parameters. However, it doesn't detail all six parameters (e.g., customInteractions, captureScreenshots).

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

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

The description clearly states the tool's purpose: 'Test accessibility of components by finding them using visible text/labels instead of CSS selectors. Automatically discovers and tests interactive elements.' It specifies the verb ('test accessibility'), resource ('components'), and method ('by finding them using visible text/labels'), and distinguishes it from sibling a11y_scanUrl by emphasizing text-based discovery rather than URL-only scanning.

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

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

The description provides clear context for when to use this tool: 'Perfect for natural language testing like 'test the Rewards section' or 'test the user menu'.' It implies usage for testing specific UI sections identified by text, but does not explicitly state when not to use it or name alternatives (e.g., when to use a11y_scanUrl instead).

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