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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds real context beyond them: a single unpaid GET, the reliability guards (public HTTPS only, 5s timeout, response size cap, no credentials), and an Ed25519 signed receipt. It does not describe failure modes or what the report looks like when the challenge is unreachable or malformed, which is the remaining gap for a verification tool.

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-loaded with the core outcome sentence, then inputs, then execution behavior, then pricing. Dense and mostly earns its length, though the parameter parenthetical duplicates schema text already visible to the agent.

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?

No output schema exists, yet the description covers the return value (a report with an Ed25519 signed receipt), the signing guarantee, the wallet proof binding requirement, and links to the contract and human page. For a 7-parameter paid verification tool this is sufficient to invoke correctly.

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 coverage is 100%, so baseline is 3; the description adds meaning by framing each argument as an advertised term that the live challenge is compared against ('the live amount, asset, network and recipient match the advertised terms'). The parenthetical recap of url/price/asset/network largely restates the schema descriptions, which caps it below 5.

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 states a specific verb and resource: checking that an x402 endpoint charges what it advertises by comparing advertised terms to the live 402 challenge. It distinguishes itself from the nearest sibling by explicitly assigning availability and latency to wever_endpoint-reliability-check.

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 for adjacent concerns ('Availability and latency stay with wever_endpoint-reliability-check') and clarifies the scope boundary that no payment is ever made. It also spells out access conditions (paid 0.10 USDC per call, 10 free signed-wallet calls per rolling 30 days) so an agent knows cost and eligibility before calling.

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