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

Annotations already declare idempotent=true, openWorld=true, non-destructive, so the safety profile is covered. The description goes beyond them with the paid nature, the $222.00 USDC price on Base or Arbitrum One, and the x402 v2 PAYMENT-SIGNATURE handshake, which is the behavior an agent most needs to know before calling. It doesn't explain what the minted receipt looks like, but an output schema exists to cover that.

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?

Purpose is front-loaded, then alternative, then payment mechanics, then the endpoint. It is terse and mostly waste-free, though the payment URL is referenced twice ('paid_url' and 'Paid URL:') and the price is stated separately from the payment protocol, which slightly fragments the call instructions.

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 paid, non-destructive, idempotent write tool with full schema coverage and an output schema, the description supplies everything an agent needs in order to invoke it correctly: payment protocol, header, network, price, endpoint, and the sibling that covers documents instead.

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 schema already documents all four parameters in detail. The description's only parameter remark ('evidence_urls + evidence_hash optional') merely restates what the required list already shows and adds no new meaning, so the baseline 3 applies.

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 opening sentence gives a specific verb and resource ('Notarize work done anywhere... verify it and mint a signed receipt') and explicitly distinguishes itself from the closest sibling by scoping attest_document to document existence. An agent can tell the two attest tools apart without opening either schema.

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 names the alternative (attest_document) and the condition that selects it, and states the payment prerequisite and protocol needed to call it. What's missing is guidance on when to supply evidence_hash versus evidence_urls, or when not to attest at all.

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