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

Annotations cover read-only/open-world safety, so the bar is lower, yet the description adds substantial traits: paid access ($0.01 USDC per call via x402 on Base or Solana), signed responses, results ordered by most-visited, and provenance from machine-readable files rather than policy pages. It still omits pagination, rate limits, and error/payment-failure behavior.

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 purpose and filter set are front-loaded, and the provenance, ordering, signature, and pricing sentences each add real value. It is dense and telegraphic in the back half ('Most visited first. Signed. Price: ...'), which is efficient but slightly harder to parse.

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 and 0% parameter coverage, the description should do more: it never describes the shape of a returned store record or the accepted value formats for the filters. It covers the domain and access model well but leaves an agent short on how to construct a valid call and what it gets back.

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 0% across 8 parameters with no enums, so the description must carry the load. It loosely maps meaning onto ships_to, agent_checkout, capability, payment (Google Pay, Shop Pay), currency, and return window, but leaves limit and platform unexplained and gives no value formats (country codes, currency codes, platform names).

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 (find), resource (stores), and dataset (weekly census of 65,000 top sites), plus the exact filter dimensions a shopping agent cares about. An agent can distinguish this from siblings like web_census or web_readiness purely from the description.

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?

Gives a clear usage context — it is for agents that need to buy, filtered by ships-to, agent checkout, payment, currency, and return window. However, it never explicitly names an alternative tool (e.g. web_census) or states when NOT to use this tool, so routing among siblings is still partly inferred.

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