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

The description adds the core calculation logic (HTS base rate + Chapter 99) and per-run credit cost, which goes beyond the openWorldHint annotation. However, it omits limitations, assumptions, data freshness, or whether the result should be treated as authoritative vs. indicative.

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 compact sentence plus a pricing line; no filler, no restating the title, and key information is front-loaded with the verb 'Calculates'.

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 2-param tool with a full output schema, the description is appropriately complete: scope, method, and pricing are all included. It only lacks a brief statement about when tariff_classification would be a better alternative, which is a modest gap.

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 parameters are already well documented. The description implies that country_or_region matters for Chapter 99 applicability, but it does not add meaningful parameter-level guidance beyond what the schema already provides.

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?

Using 'Calculates U.S. customs duties' plus the explicit method ('combining HTS base rates with applicable Chapter 99 measures') gives a clear action and resource. It also distinguishes itself from tariff classification, although it does not explicitly name sibling alternatives.

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 context clearly implies the tool is for calculating U.S. duties on imported products, but it does not state when not to use it or point to a sibling tool like tariff_classification for classification-related needs. The usage guidance is present but largely implicit.

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