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

Annotations already establish read-only behavior, so the description adds value by disclosing the daily refresh of data, the 20-result cap, and the specific output fields (general, special, and column 2 duty rates) plus links. This gives an agent a clear picture of what to expect beyond the annotation metadata.

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 sentences, front-loaded with the action and scope, followed by output details. It contains no redundant phrases and every clause contributes to understanding the tool's behavior.

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 only one required parameter, no output schema, and annotations covering the read-only safety profile, the description sufficiently describes the return payload, result limit, and data source freshness. An agent has all the information needed to invoke and interpret the result correctly.

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?

The schema already fully documents the single 'query' parameter with examples and semantics (product words or HTS prefix), providing 100% coverage. The description restates the same input types in prose without adding new meaning, so it remains at the baseline of 3.

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 verb ('Search'), a specific resource ('official U.S. Harmonized Tariff Schedule'), and the input forms (product words or HTS prefix). It also describes the output shape (up to 20 tariff lines with duty rates), which distinguishes it from the singular-lookup sibling get_us_tariff.

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 (when you need to find tariff data by product words or HTS code prefix), but it does not explicitly compare against siblings or state when not to use it. No alternatives or exclusions are mentioned, so the guidance is limited to implied context.

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