WCAG MCP Server

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

No annotations are provided, so the description carries full burden. While it states what content is returned, it doesn't disclose behavioral traits like whether this is a static list or dynamic query, response format, error conditions, or performance characteristics. The description provides basic output content but lacks operational context.

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 a single, efficient sentence that immediately conveys the tool's purpose without any redundant information. It's appropriately sized for a simple tool and front-loads the essential information about what the tool returns.

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 zero-parameter tool with no output schema, the description provides the essential information about what content is returned. However, it lacks details about the return format (e.g., structured data vs plain text), ordering, or any metadata that might accompany the principles list. The description is minimally adequate but could provide more context about the response structure.

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?

The tool has zero parameters with 100% schema description coverage, so the baseline is 4. The description appropriately doesn't discuss parameters since none exist, and the schema fully documents the empty input structure.

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 ('Lists') and the exact resource ('all four WCAG 2.2 principles') with explicit enumeration of the items returned. It distinguishes this tool from siblings like list-guidelines or list-success-criteria by focusing specifically on principles rather than other WCAG components.

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 implies usage context by specifying what content is returned (WCAG 2.2 principles), but doesn't explicitly state when to use this tool versus alternatives like get-criterion or list-guidelines. No guidance is provided about prerequisites, timing, or exclusion criteria.

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