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

Annotations already declare readOnlyHint and openWorldHint. The description adds valuable behavioral context: it is experimental, may change or be withdrawn, is not covered by the accuracy eval, and costs $0.05 per call. It also clarifies data semantics (exports total value vs general imports), which goes beyond the annotation-only baseline.

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 front-loaded with the experimental warning, followed by a concise main clause stating the data and source, and ends with the cost. At roughly 40 words, every sentence earns its place; the structure is logical and scannable.

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 simple read-only data tool, the description covers source, units, frequency, scope, and direction definitions. It does not describe the output format (no output schema exists), but the data nature (values by partner) is reasonably inferable. The experimental and cost caveats add necessary context. Overall, it is complete enough for an agent to call 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?

Schema description coverage is 100%—all four parameters are documented with types, defaults, and examples. The description adds only minor clarification, such as 'one HS chapter' and 'monthly', which largely mirror the schema. It does not compensate for any gaps or add substantial meaning beyond the schema.

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 clearly states the tool returns monthly US customs-reported trade values in dollars by trading partner for one HS chapter, from the Census international trade series. This specific verb-less but explicit resource and scope distinguishes it from all siblings, none of which mention trade flows or HS chapters.

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 provides important caveats—experimental status, instability, and cost—but does not explicitly state when to use this tool over alternatives or any exclusions. It implies usage for trade-data queries, but no alternative routing or 'when not to use' guidance is given.

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