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

Annotations already provide readOnlyHint=true and openWorldHint=true, and the description adds useful behavioral context: it accepts English or Chinese input, returns the commodity code and import duty rate, and flags codes with China-specific anti-dumping/countervailing duty. This goes beyond 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?

The description is two focused sentences with no filler. The first sentence states the primary action and inputs, and the second adds the important China-specific flag behavior. Key information is front-loaded and every sentence earns its place.

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?

Since there is no output schema, the description adequately conveys what the agent will receive: a commodity code, import duty rate, and a flag for China-specific anti-dumping/countervailing duty. It is complete for most use cases, though it does not mention behavior when both product and commodity_code are supplied or when no match is found.

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 100%, so the description does not need to redefine the parameters. It adds minor context by clarifying that the product description can be in English or Chinese and that the source country is China, but this does not substantially extend the schema's existing parameter documentation.

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 uses a specific verb ('Find') and a concrete resource ('UK commodity code and import duty rate'), and clearly states the accepted input forms: product description in English or Chinese, or a commodity code. It also adds a distinctive behavior—flagging China-specific anti-dumping or countervailing duty—which separates it from sibling tools like check_anti_dumping.

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 when to use the tool: to look up a UK duty rate and commodity code from a product description or code, and to see China-specific AD/CVD flags. However, it does not explicitly name alternatives or state when not to use it, such as when only a detailed anti-dumping check is needed rather than a general duty-rate search.

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