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

The description adds meaningful behavioral context beyond annotations: it discloses a one-blocker-per-offer cardinality limit ('at most one aggregate count is accepted per offer') and privacy guarantees ('No wallet address, token, transaction hash, query, or free-form text is published'). These details complement the annotations without contradicting them.

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?

Three dense sentences carry the precondition, core behavior, cardinality constraint, privacy guarantee, and sibling routing. The most important usage condition is front-loaded, and every sentence earns its place without repetition.

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 tool with four fully documented parameters and an output schema, the description covers when to call it, what it reports, its limits, its privacy behavior, and what to use instead after payment. Nothing essential is missing for an agent to invoke it 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?

The input schema already documents all four parameters with 100% coverage, including enum meanings and the private nature of paymentOffer. The description reinforces the closed-vocabulary nature and non-publication behavior, but it does not add substantial new semantics beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 clearly states the verb 'Report' and the resource 'checkout blocker,' and immediately conditions it on a signed KnownFix checkout that cannot proceed before a payment hash exists. It also isolates the tool from siblings by explaining it reports exactly one closed-vocabulary blocker tied to the valid offer.

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?

The description gives an explicit precondition ('Use only after a signed KnownFix checkout cannot proceed before a payment hash exists') and an explicit exclusion ('Do not call after payment'), naming the alternatives get_fix, get_skill, and audit_endpoint. This leaves no ambiguity about when to use the tool versus its siblings.

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