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

With zero annotations, the description carries the full burden and does so: it discloses the exact price ($0.01 USDC on Base), that payment 'settled before the tool runs' (i.e., you pay even if results are poor), a free preflight with a 3/day cap, spend-limit settings, and an honest caveat that funded delivery through x402-proxy is unverified. These are exactly the consequential traits an agent cannot get from schema or 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?

It is front-loaded with purpose and triggers, but roughly half the text is payment plumbing (x402, spendLimitPerTx, /llms.txt pointer) that sits awkwardly in a tool description, and the reuse-until-expiry rule is stated twice (in the trigger sentence and again after the return contract). Every element is relevant, but the block is denser and longer than a caller skimming for 'what does this do' needs.

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 describe returns — and it does, naming the verdict enum, the exact call, a fallback, valid_until and recheck_when. Pricing, payment mechanics and the preflight path are covered. The remaining gap is failure behavior: it never says what the caller gets (or is charged) when no provider matches the filters.

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 86%, so the baseline is 3, and the description adds selective meaning on top: 'by need' maps to the free-text query, the ranking evidence (independent payers, calls-per-payer, last settlement) explains why min_payers and price filters exist, and the payment_signature two-step flow is restated coherently. It does not clarify limit/pagination semantics or what a zero-result search with filters returns, so it stays short of a 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 gives a concrete verb+resource pair: it 'finds providers by need and ranks them by real economic evidence' and returns USE/WATCH/AVOID verdicts. That is clearly distinguishable from the vetting/forecasting siblings, though it never names ghost_commerce_vet or explains the split between searching for providers versus vetting a known one. The opening line is a decision-oriented aphorism rather than a statement of function, pushing the actual purpose to the third sentence.

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 enumerates explicit invocation triggers — provider unknown, a held decision past valid_until, or a material change in price/health/verdict/funding — and pairs them with a negative rule: reuse a held decision until it expires or a trigger fires rather than asking again. That is precise when-to-use and when-not-to-use guidance in one place, with no inference required.

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