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

Goes well beyond the annotations: discloses privacy ('we never see it'), the payment mechanism (x402 v2 PAYMENT-SIGNATURE header, $0.25 in USDC on Base or Arbitrum One), the paid endpoint, and a docs link. That is operational context an agent cannot get from readOnlyHint/destructiveHint alone.

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?

Front-loads the core purpose before protocol logistics, and every sentence carries actionable information. The payment/protocol sentences are dense but justified for a paid tool, though they read a bit like boilerplate appended to the description.

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?

Covers purpose, privacy model, payment flow, and endpoint, and return values are covered by the output schema. Remaining gap is the absence of any contrast with attest_work for an agent choosing between the two attestation tools.

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%, so the baseline is 3. The description's only parameter remark, 'document_name is an optional label,' restates what the schema already says and adds no syntax or format detail.

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?

Opens with a specific verb and effect: 'Prove a document existed' via SHA256 hash into a signed, hash-chained attestation. It partially differentiates siblings by routing live URLs to check_url_custom, but never contrasts with the closely named attest_work, leaving the agent to infer the distinction.

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?

Gives an explicit alternative for a near-miss case ('Live URLs: check_url_custom'), which is exactly the kind of routing guidance that prevents mis-selection. It lacks a when-not-to-use rule for the attest_work sibling, so a small gap remains.

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