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

Annotations only declare it as a non-destructive, non-idempotent, open-world read; the description adds substantial behavior an agent cannot get elsewhere: it is a paid endpoint at 0.10 USDC per call on Base via x402 exact, with 10 signed-wallet free calls per rolling 30 days, and it requires binding X-Wever-Wallet-Proof to the exact JSON arguments and route. It also discloses failure semantics (a series the venue or sample does not carry is reported unavailable with its reason) and that the return carries an Ed25519 signed receipt, which is consistent with the read-only, non-idempotent annotations.

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?

The core purpose is front-loaded in the first sentence, followed by edge-case behavior and then operational facts (endpoint, price, auth binding, receipt, contract link). It is dense but every clause carries information. Minor redundancy between 'POST /api/market-data-check' and the paid-URL sentence keeps it from a 5.

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 payment-gated tool with no output schema, the description covers the things an agent must know before calling: cost, free-tier limits, required wallet-proof binding, and the shape/signing of the result. It stops short of detailing error responses or what the signed receipt attests to, but those are secondary for correct invocation.

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 the market/sample oneOf, the venue enum and every threshold default. The description mirrors the venue types and mentions 'optional thresholds' without adding syntax or validity rules beyond the schema. Baseline 3 is appropriate; the description neither compensates for nor undermines the schema.

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 gives a specific verb+resource: submit a market identifier or a supplied market data sample and receive a signed evidence report covering mark price freshness, index sanity and funding recency. The scope is concrete and well bounded. It does not, however, differentiate itself from near-name siblings such as wever_data-evidence-check, wever_terms-evidence-check or wever_listing-check, which also produce 'evidence reports'.

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?

Usage is implied by the two input paths (live venue identifier vs. supplied sample) and by naming the three supported venues, so an agent can infer which branch applies. But there is no explicit when-to-use / when-not-to-use guidance and no routing signal pointing to the sibling check tools, which an agent facing dozens of *-check tools genuinely needs.

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