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

With only readOnlyHint/openWorldHint in annotations, the description adds material facts: the call costs $0.01 USDC paid via x402 inside the call, failed calls are not charged, and the tool reports what Agoranome already holds rather than fetching fresh. It also discloses the post-settlement behavior (USDC transfer on Base, quote match, optional buyer-side receipt) beyond what annotations cover.

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 verdict contents and mode split are front-loaded and every sentence carries information (what is checked, when to use, cost model). The middle sentence is a dense run-on list, but it is not padding.

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?

There is no output schema, so the description must convey return content and does: it enumerates the verdict's components and the settlement-mode proof fields. Remaining gaps are minor — no pagination/format detail, and the share/receipt publication side effect is only alluded to.

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 all seven parameters are already documented, making 3 the baseline. The description only adds meaning for tx= (settlement mode) and loosely gestures at pay_to and expected_price; share, max_price, and accept_proof get no extra framing in the prose.

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 specific verb and resource: a signed verdict on one x402 offer built from Agoranome's held data, enumerating what the verdict covers (Fair Offer block, pay-to, price vs listing/quote, verified deliveries, policy tiers). It is clear what the tool does and has a distinct two-mode shape, but it never names the nearby siblings (check_offer, check_fair_offer) it likely overlaps with, leaving that differentiation to inference.

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 states the operating moment explicitly ("before paying an x402 seller", "Use when an agent needs seller evidence at the moment of payment") and defines the tx= variant as the post-payment settlement check, so an agent knows which mode to pick. It stops short of stating when NOT to use it or pointing to an alternative sibling tool.

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