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

Annotations already provide readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds valuable context beyond annotations by specifying the price ($2.50 USDC via x402) and the specific evaluation dimensions, which helps the agent understand expected behavior without contradicting annotations.

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 two sentences, with the main purpose front-loaded and the price statement concise. Every word serves a purpose; there is no redundancy or filler.

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?

The description covers the tool's purpose and price, but lacks any information about the output format or return value, especially since there is no output schema. It also does not provide guidance on how the input metadata should be structured beyond 'supplied metadata', leaving an agent with partial information for a complete interaction.

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 zero named parameters and a generic additionalProperties schema, the baseline is 4 per the rubric. The description adds meaning by indicating that the input object is the metadata to be checked, even though it does not detail the object's structure. This is sufficient given the open schema.

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 a specific verb ('Check') and the resource (OpenAPI, MCP, A2A, or x402 metadata), along with the aspects evaluated (discoverability, input clarity, payment hints, bounded outputs). This distinguishes it from sibling tools like json-quality or schema-repair by focusing on agent endpoint metadata.

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 use by saying 'Check supplied ... metadata', but it does not explicitly state when to use this tool versus alternatives, nor does it mention any exclusions. No sibling tool is referenced, so the usage context is only inferred.

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