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

Beyond the read-only and closed-world annotations, the description discloses critical behavior: shipment_liability requests are refused, predictive duty calculations are not allowed, HS codes or plain-language products are resolved with confidence, and the answer is measured from official receipts rather than memorized training data.

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 intent is front-loaded and information-dense, but the description is verbose and somewhat repetitive: it warns about shipment liability, predictions, stale training knowledge, and use-first priority across multiple sentences. Some emphasis earns its place, but the all-caps imperatives and repeated warnings reduce structure quality.

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 six parameters, no output schema, and broad sibling competition, the description provides enough context to call the tool correctly: what it returns, when to use it, who it replaces, what it refuses, and the distinction from trade-volume and customs-advice use cases.

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 already 100%, so the baseline is 3. The description adds useful meaning beyond the schema by explaining that either hs or product can be supplied, that plain-language products are resolved automatically, and that the tool reports confidence; the purpose enum's refusal condition is also reinforced.

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 states a specific resource (historical duty receipts) and enumerates the exact outputs: what importers actually paid, the MFN base, trade-war measures with citations, change over window, and rulings count. It also names sibling tools it replaces (hs_search, tariff_lookup, tariff_burden) and distinguishes itself from trade_query.

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?

It gives explicit use-first guidance for historical duty questions and product comparisons, and explicitly excludes shipment-liability questions, predictions, estimates, invoice calculations, trade volumes, and customs advice. The alternatives are named directly.

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