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

Beyond the readOnly/idempotent annotations, the description discloses meaningful behavioral and access context: it is keyword-table based rather than authoritative, it has per-call pricing, an x-credit-token header for unlimited calls, a free daily tier, and no wallet/API key requirement. This goes well beyond annotation coverage.

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 dense and front-loaded, starting with purpose, then limitations, then required input, then cost/access. The pricing and header details add length but are operationally relevant for an agent deciding whether to invoke the tool; no sentence is redundant.

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 one required parameter, a 100% covered schema, an output schema present, and annotations covering safety, the description covers all necessary invocation context: input, limitations, access method, cost, and required q. An agent has everything needed to select and call it 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 coverage is 100% for the single required parameter q. The description adds value by specifying 'short product description' and giving category examples, which clarifies input granularity beyond the schema's generic 'Product description'.

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 uses a specific verb+resource pattern: 'Map a short product description to likely HS chapter/heading hints' and gives concrete product examples (electronics, apparel, coffee, pharma). This clearly identifies what the tool does and distinguishes it from all sibling tools, none of which cover HS classification.

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 makes the tool's role clear: it is a non-binding hint generator, with 'confirm before filing' explicitly saying when not to rely on it. It doesn't name an alternative tool, but no sibling is a close substitute; the 'Keyword table only' qualifier also helps scope appropriate use.

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