Accessibility MCP Server

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

With no annotations provided, the description carries full burden but only mentions what inputs are supported. It doesn't disclose behavioral aspects like whether this is a read-only operation, potential performance impact, error handling, authentication needs, rate limits, or what the output format looks like. The description is minimal for a tool that performs automated testing.

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 efficiently structured in a single sentence that communicates the core functionality. It's appropriately sized for a tool with good schema documentation, though it could be slightly more informative given the lack of annotations.

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?

For a testing tool with no annotations and no output schema, the description is insufficient. It doesn't explain what the audit returns, how results are structured, error conditions, or performance characteristics. The context signals show complexity (nested objects, 2 parameters), but the description doesn't provide enough information for an agent to understand the tool's behavior fully.

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 100%, so the schema already fully documents both parameters. The description adds minimal value by mentioning the types of URLs accepted, but doesn't provide additional context beyond what's in the schema. Baseline 3 is appropriate when the schema does the heavy lifting.

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 specific action ('Run an accessibility audit'), technology used ('using axe-core via Playwright'), and supported input types ('URLs, local file paths, and localhost URLs'). It distinguishes from sibling tools by specifying the axe-core engine rather than Lighthouse or WAVE.

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 mentions what the tool supports but provides no guidance on when to use this tool versus the sibling tools (lighthouse_audit, wave_audit). There's no mention of comparative advantages, use cases, or prerequisites for choosing axe-core over alternatives.

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