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

With readOnlyHint/openWorldHint/destructiveHint already covering the safety profile, the description adds genuinely new behavioral context: no API key required, a caveat that gateway trade and nationwide duty receipts are different universes surfaced in the response, and an explicit refusal rule about a nationwide-duty/gateway-value quotient. Those are operating constraints the agent could not infer from annotations.

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 content is dense and earns most of its space, but it opens with a two-sentence prohibition about a quotient calculation rather than with what the tool does, burying the purpose behind a guardrail. Front-loading the country-profile purpose would make routing faster.

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 four-parameter read tool with no output schema, the description thoroughly enumerates what comes back (volume, value, gateways, chapters, burden, studies) and the universe mismatch caveat. The only meaningful omission is any explanation of the `detail` verbosity enum, which affects how much the agent gets back.

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 50% and the description only implicitly maps parameters: 'with the trend' gestures at months, 'top commodity chapters' at top_n, and origin is documented in the schema itself. The `detail` enum (answer/standard/full) has no description in either the schema or the prose, which is the most consequential unexplained control for response sizing.

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 names a specific verb+resource: one origin country's whole profile, enumerating containerised import volume/value through 8 gateways, trend, top commodity chapters, receiving gateways, effective tariff burden, and pre-registered studies. It explicitly distinguishes itself from trade_query, tariff_burden, tariff_story, and compare by naming each where relevant.

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 states when to use it ('OPEN any country-level question', with worked examples), what to use instead of it ('Do NOT use for a specific HS code (tariff_story) or a two-way comparison (compare)'), and which siblings it replaces (trade_query and tariff_burden fired separately). Both the positive and negative routing conditions are explicit.

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