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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safe read-only profile is covered without the description. The description adds the 'partial answer at 4/6 digits' behavior for the input, which is useful, but says nothing about permissions, caching, or response shape beyond listing the fields.

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 tight sentences; the output facets are front-loaded followed by the actionable input rule. No redundant padding and nothing that can be dropped without losing information.

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 two well-documented parameters and no output schema, the description usefully enumerates the returned information (scope, category, indirect emissions, default value), compensating for the absent output schema. It is nearly complete, though a note on how country defaults when omitted would close the last 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 coverage is 100%, so the baseline is 3, but the description adds genuine meaning beyond the schema: it ties cn_code to the customs declaration and explains that 4/6 digits yield only a partial answer, and it frames the country parameter as driving the EU default value. That extra operational nuance lifts it above baseline.

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 gives a specific verb+resource (check EU CBAM scope of a CN code) and enumerates the exact facets returned: in-scope status, aggregated goods category, indirect-emissions counting, and EU default value. It is clearly more than a restatement of the name, though it doesn't explicitly distinguish itself from the sibling cbam_default_value, which overlaps on the default-value facet.

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 only guidance is 'Use the 8-digit CN code of the customs declaration (4/6 digits give a partial answer)', which is input-format advice rather than when-to-use guidance. It offers no explicit conditions for choosing this tool over cbam_default_value or estimate_cbam_cost, so usage is only implied.

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