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

Annotations already cover read-only and closed-world behavior, but the description adds substantive context beyond them: it is free for signed-in users (implying an auth requirement), makes no AI call (deterministic), and explicitly reports the HS-description check as 'not checked' rather than silently omitting it. That limitation disclosure is exactly what an agent needs to interpret results correctly.

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 purpose is front-loaded and the check list is well structured, but the entire description is duplicated verbatim in Vietnamese, doubling length without adding information for an agent. Every sentence in the English half earns its place; the mirror half is pure redundancy.

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 complex nested-input review tool with no output schema, the description covers what is checked, what is not, and the auth/cost profile, which is most of the behavioral burden. It is still thin on how results are surfaced (a sibling ket_qua_soat exists) and on the meaning of the less obvious input fields.

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 0%, so the schema supplies names and formats but no meaning. The description partially compensates by mapping check topics to likely fields (description→moTa, duty rate→thueSuatKhai, ACFTA/Form E→coFormE, licences→giayPhepCo, value→triGia), but never documents the line-item array, loaiHinh, or ngayDuKienDangKy, and gives no format or constraint guidance.

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 states a specific verb and resource ('Reviews a draft customs declaration line by line before it is filed') and enumerates the exact checks performed (description quality, duty rate, ACFTA/Form E, licences, value sanity, technical file). It also draws a boundary against the description-to-HS-code check that sibling tools handle, though it does not name that sibling explicitly.

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 implies the usage window ('before it is filed') and discloses the one check it does not run, which helps an agent avoid misusing it. However, no alternative tool is named for the omitted HS-code check, and there is no explicit when-to-use / when-not-to-use routing beyond that single negative statement.

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