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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: the DZ-default / TN-MA-key-required auth behavior and the failure modes (country_not_available, key_required). It does not, however, describe pagination or result-size behavior. Given annotations carry the safety burden, the added auth/error detail lands this at a solid but not exceptional level.

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?

Three sentences, front-loaded with what the tool returns and who consumes it next. The country variants are packed densely but each clause is functional; no filler or tautology.

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 carries the return burden and does so reasonably: chapters with two-digit codes plus titles, in a chosen language. It also states dataset limits, which prevents wrong expectations. Pagination/ordering behavior is the only notable gap.

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%, so lang, country, and section are all documented in the schema, including the enum, defaults, and per-country error behavior. The description restates the section format ('two-digit codes') and the section example but adds little syntax or format detail not already present. Baseline 3 applies when the schema does the heavy lifting.

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 (list) and resource (chapters of a customs tariff section) with the exact granularity ('two-digit codes ... with their titles'). It also implicitly separates itself from customs_tariff_sections, which it names as the prerequisite sibling, so an agent can tell the two apart without opening either schema.

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?

Explicitly says 'Use it after customs_tariff_sections', giving ordering and prerequisite. It also gives negative scope ('holds no duty rates and no tariff lines below the chapter level') and per-country conditions (TN/MA need an API key), which tells the agent when this tool is and is not the right choice.

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