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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds real behavioral detail beyond them: a four-digit heading returns contained CHPL subheadings and prompts for HS6, and NERAI refuses to infer a classification. That edge-case behavior is exactly the kind of context annotations cannot express.

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?

Two sentences, front-loaded with the core action and the definition, then the input constraint. The second sentence is dense but each clause (four-digit behavior, rationale, no-inference rule) carries information rather than filler.

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?

There is no output schema, so the description bears some burden for describing return values; it explains the four-digit return case but never says what a successful six-digit lookup returns (match/no-match, control details, etc.). Annotations handle the safety profile, leaving this the main gap for a single-parameter lookup tool.

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 100% and the schema says 'ideally six digits', but the description sharpens this into a hard requirement and explains the consequence of supplying only four digits. That is genuine added meaning about the parameter beyond the schema's example.

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?

States a specific verb (look up) and resource (an HS code against the Common High Priority List) and even expands the acronym's meaning. It is clearly distinct from the country- and corridor-oriented siblings, though it does not explicitly contrast itself with the nearest sibling, get_commodities.

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 conveys context (goods jointly flagged by the US, EU, UK and Japan as most frequently diverted) and the input precondition of a six-digit code, but it never states when to prefer this tool over alternatives such as get_commodities or find_enforcement_precedent. Usage is implied rather than routed.

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