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

No annotations are present, so the description carries the full disclosure burden. It conveys that results are estimates rather than guarantees and confines coverage to US MFN + Section 301 tariffs — genuine behavioral context. But it stays silent on whether duty rates are fetched live, how 'category' maps to HS codes internally, and how an optional tariffRate overrides built-in rates, which are useful behavioral traits for a calculator with no other disclosure.

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?

Two short sentences, both load-bearing: the first states verb, resource, and method; the second states jurisdiction scope. No filler, no restatement of schema field names, and the essential purpose is front-loaded.

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?

With no output schema, the description usefully names the expected outputs ('import duties and landed cost'), covering the return-value concept. Gaps remain: whether freight is required to produce landed cost (it is optional in the schema), how tariffRate and category interact, and behavior for categories outside US MFN/301 coverage. Adequate for a single-purpose calculator, but not 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 coverage is 100%, so the baseline is 3. The description adds one meaningful link: 'by HS code category' clarifies that the weakly described 'category' parameter means an HS code category, which the schema ('Product category') alone does not convey. It also implies freight feeds into the landed-cost computation. It does not explain precedence between tariffRate and category, a minor residual gap.

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 ('Estimate') with a concrete resource ('import duties and landed cost') and a stated method ('by HS code category'). The 'US MFN + Section 301' clause gives precise jurisdiction scope and cleanly differentiates it from the many calculate_* siblings (tax, loans, ROI, reseller profit), none of which handle import duties. An agent can identify this tool without ambiguity.

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 scope line 'Covers US MFN + Section 301 tariffs' implies the tool is for US import estimates, which is an implied boundary. However, it never names an alternative or states when-not-to-use (e.g., non-US tariff regimes, or sales tax via get_sales_tax_rate). Selection logic is left mostly to inference.

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