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

Goes well past the annotations by disclosing the ordered check pipeline (format, algorithm, family, key id, encoding, signature, type, issuer, receipt fields, report digest) and that the first failure is named, which tells the agent how partial failures surface. It also states the commercial and auth model — 0.10 USDC per call on Base via x402, 10 signed-wallet free calls per rolling 30 days, and the requirement to bind X-Wever-Wallet-Proof to the exact JSON arguments and route — which an agent cannot infer from readOnlyHint/openWorldHint 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?

Purpose and scope are front-loaded in the first sentence, and the check pipeline plus payment terms are dense but information-bearing. It loses a little to cramming — the bare "POST /api/receipt-verify" path and the human-facing page URL are marginal for an agent that already has the tool, and the multi-clause sentences could be split.

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?

With no output schema, the description does carry the return burden and covers it in outline: a report plus an Ed25519 signed receipt, and a named first-failing check on failure. Combined with full schema coverage and annotations, that is nearly complete; only the shape of the returned report and the fields inside it are left implicit.

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 both parameters (including the report digest matching rule and the anyOf receipt shapes) are already documented in the schema. The description restates the accepted forms at a high level ("compact token or the receipt object, plus the optional report") without adding format detail, so it sits at the baseline rather than adding meaning.

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?

States a specific verb and resource ("verify a Wever signed receipt against Wever's published Ed25519 keys") and adds the outcome semantics: "state what it proves, or exactly why it fails." It also enumerates the receipt families it covers, which separates it from siblings like wever_receipt-passport or wever_data-evidence-check that produce rather than validate receipts.

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 makes the input situations explicit ("Accepts the compact token or the receipt object, plus the optional report it came with") and scopes which receipt types are in play. What it lacks is an explicit routing statement — it never says when to prefer this over a sibling such as wever_receipt-passport or wever_verify-and-release — so usage is clear but not fully disambiguated.

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