Accessibility 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 and does so effectively. It reveals the API key requirement, the temporary server behavior for local files, and the supported input types. However, it doesn't mention potential rate limits, error conditions, or what the audit output looks like, which would be helpful for a tool with 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 perfectly concise with three sentences that each add distinct value: the core purpose, the API key requirement, and the local file handling behavior. There's zero redundancy or wasted words, and the information is front-loaded with the most important details first.

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 tool with no annotations and no output schema, the description provides adequate but incomplete context. It covers the purpose, prerequisites, and input handling well, but doesn't describe what the audit returns, potential limitations, or error scenarios. Given the complexity of an accessibility audit tool, more information about output format would be beneficial.

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?

With 100% schema description coverage, the input schema already documents both parameters thoroughly. The description adds some context about URL types and the temporary server behavior, but doesn't provide additional semantic meaning beyond what's already in the parameter descriptions. This meets the baseline expectation when schema coverage is complete.

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') and resource ('using WAVE API'), distinguishing it from sibling tools (axe_audit, lighthouse_audit) by specifying the WAVE technology. It provides a complete verb+resource+technology combination that leaves no ambiguity about what this tool does.

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 about when to use this tool ('Supports URLs and localhost URLs. Local files are automatically served via temporary local server'), but doesn't explicitly mention when NOT to use it or directly compare it to the sibling tools (axe_audit, lighthouse_audit). The API key requirement is mentioned but not framed as an alternative usage scenario.

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