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

Annotations already declare the tool read-only, so the description doesn't need to repeat that. It adds behavioral context by specifying the exact data points returned (total exports, top countries, year-to-date change, states) and the authoritative Census source. It doesn't discuss pagination or data freshness, but with readOnlyHint covering safety, this is sufficient.

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?

A single, well-organized sentence front-loads the authoritative scope ('Official U.S. Census Bureau statistics for one product at the HS 4-digit level') followed by a colon and a compact list of precisely what the tool returns. Every phrase earns its place.

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 one-parameter read-only tool without an output schema, the description gives an agent enough information to decide and invoke: it names the required input type, the scope, and the output components. The only minor gap is the unspecified number of 'top' destinations and the exact time window for 'year-to-date', but these are unlikely to block correct usage.

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 only parameter, hs4, is fully documented in the schema with examples. The description reinforces that the tool works for one product at the HS 4-digit level, but adds no new meaning beyond the schema, so the baseline of 3 applies.

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 identifies the tool's function: it provides official U.S. Census Bureau statistics for a single HS 4-digit product, including total exports, top destination countries with year-to-date change, and top shipping states. This precise breakdown distinguishes it from sibling tools like find_us_exporters or get_us_exports_by_state.

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 it—when a product-level view of export markets is needed—but it does not explicitly mention alternatives or state when not to use it. The overlap with get_us_exports_by_state (which also touches state export data) is not addressed, leaving some ambiguity.

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