Dated, signed proof that a document set existed — a Merkle root, the leaves, and a real inclusion proof (PAID $2.00)

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

Annotations already declare this a non-read-only, open-world, non-idempotent, non-destructive operation; the description usefully adds that each call costs $2.00 via x402 on Base. It does not explain what a repeated call does to the anchor (relevant given idempotentHint=false), nor whether payment is charged on failure.

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?

Two short lines with the artifact described first and the payment/route facts second; no filler. It does repeat the title verbatim, which is wasteful rather than harmful.

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?

An output schema exists so return values need no prose, but this is a paid, non-idempotent mutation with four entirely undocumented inputs. In particular an agent cannot tell from the description whether anchored_at lets it assert a backdated existence claim or whether notarise changes the legal weight — critical gaps for a proof-of-existence tool.

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 0% across four parameters, so the description must compensate and largely fails. 'Merkle root' and 'the leaves' only loosely hint at the merkle and documents parameters; notarise (a boolean) and anchored_at (a caller-supplied timestamp with a security-relevant meaning) get no explanation at all.

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 names a concrete artifact produced — a Merkle root, the leaves, and an inclusion proof over a document set — so the agent knows exactly what it gets back. It does not, however, differentiate itself from near siblings such as v1_x402_anchor or v1_audit_evidence_package.

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 only routing information is the HTTP path and the payment rail (2.00 USD x402/base/usdc on eip155:8453). There is no statement of when to anchor versus use an alternative proof tool, nor prerequisites such as needing a funded x402 pass first (v1_pass_purchase / v1_budget_preflight exist as siblings).

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