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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorldHint=false, so safety is covered. The description adds genuinely useful behavior beyond that: it discloses the full response surface (reply rates, import metrics, supplier mix, channel/disclosure rules) and states that rules_coverage and rule_pointers reveal what rules TradeGraph actually holds when item is supplied. It does not say anything about response size, latency, or what happens when country or item data is missing.

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 front-loaded as a single dense enumeration, which is the right shape, but it sprawls into a very long sentence with nested parentheticals and a second sentence that cross-references output fields. Every clause is informative, yet the packing makes it slower to scan than a short bulleted content list would be.

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 no output schema, the description must carry the return-value burden and largely does, enumerating each section of the brief plus the two conditional rules fields. For a four-parameter, read-only tool this is close to complete; only response shape/size and empty-result behavior are left unstated.

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% and each parameter is exhaustively documented in-schema, including trait detection and fallback to live UN Comtrade for arbitrary HS4 codes. The description adds only one piece of meaning beyond that: the conditional link that supplying item causes rules_coverage and rule_pointers to describe the held rules for that product in that country. Useful but marginal, so baseline 3 is right.

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 the resource (one country) and enumerates the specific contents it returns: reply rate, import size/growth/Korea share, supplier mix, reply rates by industry, top US states, channels and disclosure rules. That is concrete enough to distinguish it from narrower siblings such as reply_pace or buyer_targets. It lacks an explicit verb ('retrieve/report'), opening with 'Everything TradeGraph knows', so the read-only nature is inferred rather than stated.

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?

Usage is implied by the breadth of the enumeration — this is the comprehensive per-country brief — and the parenthetical '(for the US)' signals a regional scope limit. However, no sibling is named as the alternative for narrower questions, and there is no explicit when-not-to-use guidance (e.g. 'use market_scan for multi-country comparisons', 'use reply_pace for pacing detail'). The agent must infer routing from the content list.

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