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

With no annotations, the description carries the full burden and does well: it discloses the pay-per-call cost ($0.002 USDC or equivalent credits) and enumerates the data returned, which substitutes for the missing output schema. It omits what happens on an invalid or unknown product_id and whether payment is automatic.

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?

One front-loaded sentence stating the action, cost, and returned fields, followed by a compact usage example. Every element earns its place with no filler.

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 simple single-lookup tool with no output schema and no annotations, the description covers cost, the full return payload, and an invocation example. The remaining gap is failure behavior for a missing product and how product_ids are sourced.

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?

Only one parameter and schema description coverage is 0%, so the description must compensate. The example product_detail(product_id='gpu-market') usefully shows the expected slug-style value, but nothing states format constraints, case sensitivity, or whether IDs come from list_products.

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?

Uses a specific verb and resource ("查单个数据产品", query a single data product) and enumerates exactly what the profile contains (tools, call counts, buyers, sales, uptime, license, settlement address). It is implicitly distinct from list_products (single vs. list), but never names the sibling to make the distinction explicit.

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 implies usage (you need one product's full record) and discloses per-call pricing, which is genuinely useful for deciding to call. However, it gives no when-not-to-use guidance and never points to list_products or marketplace_catalog as the way to discover a valid product_id first.

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