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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the description's job is to add context — and it does, by disclosing the returned structure (path, parent, siblings, children) and the notable inclusion of residual 'other' lines, which is non-obvious behavior. It does not state what happens for a non-existent or malformed code, leaving that gap.

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 English sentence is well front-loaded and dense with useful detail, but the second sentence is a verbatim Vietnamese translation carrying no new information, effectively doubling length for zero added semantics. Acceptable if bilingual parity is intentional, but it does not earn its place on information grounds.

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 only one parameter, no output schema, and annotations already declaring read-only behavior, the description's enumeration of return fields is the most important thing it can do, and it does so. The remaining hole is error/miss behavior when the supplied code is invalid or unknown.

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 0% and the single parameter 'maHs' is documented only as a bare string. The description compensates with the crucial constraint that it is a 4-8 digit HS code, which excludes 2-digit chapter queries and is the key semantic the agent needs. It does not describe validation or error handling for out-of-range codes, so it stops short of full compensation.

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 and resource — 'Returns the Vietnam HS nomenclature tree around a code (4-8 digits)' — and enumerates the exact output shape (path, parent, siblings, children, residual 'other' lines). This is far more specific than a sibling like 'tim_ma_hs' or 'tra_chu_giai', but the description never names an alternative tool, so the differentiation is inferred rather than explicit.

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?

There is no when-to-use versus when-not guidance and no mention of sibling tools such as tim_ma_hs (code lookup) or phan_loai_hs (classification). The agent must infer from the resource noun that this tool is for hierarchy expansion around a known code, but nothing in the text says so.

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