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

Annotations already cover read-only, open-world, non-destructive, and non-idempotent traits, while the description adds substantial operational context: 0.10 USDC cost, free quota, wallet-proof binding, one-header image reads, and an Ed25519 signed receipt. These are exactly the behavioral and cost details an agent needs before calling a paid check.

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 description is front-loaded with purpose and remains information-dense, with most sentences carrying useful payment, auth, or output details. However, the single paragraph mixes purpose, cost, auth, and documentation links without structure, and "It checks the listing as submitted" is somewhat redundant.

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 an 8-parameter paid tool with no output schema, the description covers the API route, payment and wallet-proof requirements, and the report's high-level contents including a signed receipt. It leaves detailed response fields and error/refund behavior to the contract link, so it is strong but not fully complete.

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 63%, and the schema itself documents marketplace and required_fields. The description lists the main payload fields and explains that price sanity uses msrp, original_price, cost, quantity, and quoted text prices, but it does not clarify required_fields replacement behavior or marketplace's role, so it only partly compensates.

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 action and resource: submit a product listing and receive a signed report on missing fields, image reachability, and price sanity. The listing-specific scope clearly separates it from sibling check tools such as invoice-check or market-data-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?

The intended use is implied by "checks the listing as submitted," suggesting pre-submission validation, but there is no explicit when-to-use/when-not guidance or named alternative sibling. Payment and endpoint details help invocation but do not provide routing guidance.

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