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

With no annotations, the description carries the full burden, and it does disclose one genuinely important behavior: paid work is refused over MCP and delivered only via x402. It says nothing about response content, whether any auth is needed to read the explanation, or what happens on the public path.

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?

A single dense sentence with the subject front-loaded and the payment constraint following it; nothing is redundant. The semicolon construction packs two ideas efficiently, though it is slightly clipped.

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-param, no-output-schema informational tool, the description should indicate what the explanation contains (e.g., pricing, endpoint, or requirements), and it only supplies the endpoint shape. It is adequate to identify the tool but thin on what the agent gets back.

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 takes zero parameters, so per the rubric the baseline is 4. There is no parameter behavior left to clarify and the description does not misrepresent the empty input.

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 states a specific subject (the paid full-matrix check path) and implicitly disambiguates from the name's suggestion that this tool performs a check -- it explains one instead. That distinction is useful against siblings like annsurv_paths, though the verb 'explains' stays generic about what the tool actually returns.

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?

It implies usage by routing paid work away from MCP to x402 on POST /check, so an agent can infer this tool is for understanding the paid path. However, there is no explicit 'use this when' clause and no named alternative tool within the annsurv_* family.

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