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. It states the tool returns counts but doesn't disclose behavioral traits like whether it's read-only (implied by 'returns'), performance characteristics, error handling, or output format. For a tool with no annotation coverage, this leaves significant gaps in understanding how it behaves.

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 front-loads the core functionality ('returns counts of success criteria') and specifies the grouping method. Every word earns its place with no redundancy or unnecessary detail, making it easy to scan and understand quickly.

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 low complexity (1 parameter, 100% schema coverage) and no output schema, the description is minimally adequate. It covers the basic purpose but lacks details on output format, error cases, or usage context. Without annotations, it should do more to compensate, but the simplicity of the tool keeps it from being severely incomplete.

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%, with the single parameter 'group_by' fully documented in the schema (including enum values). The description adds minimal value beyond the schema by mentioning the grouping options, but doesn't provide additional context like default behavior or examples. 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.

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

The description clearly states the tool's purpose with a specific verb ('returns') and resource ('counts of success criteria'), and specifies the grouping dimension ('by level, principle, or guideline'). However, it doesn't explicitly differentiate from sibling tools like 'list-success-criteria' or 'get-success-criteria-detail', which might provide similar data in different formats.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, context, or compare it to sibling tools like 'list-success-criteria' (which might list rather than count) or 'get-success-criteria-detail' (which might provide detailed info). Without this, users must infer usage from the name and description alone.

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