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

Annotations declare readOnly and idempotent, but description adds valuable context: data source (財政部關務署) and monthly sync, comprehensive list of tax types, exceptions (e.g., 0% rate still applies to all imports), and regulatory authorities. No contradiction with annotations.

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 a single dense sentence with multiple semicolon-separated clauses. It is information-rich, listing many tax types and exceptions, and every clause adds value. Slightly long but justified for the tool's complexity.

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?

Given the tool's complexity, the description covers all essential aspects: purpose, scope, usage alternatives, data source, freshness, and full result contents. Output schema exists so return details need not be described. It is complete for an agent to select and invoke 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 description covers 100% of the single parameter with format and examples. The description repeats the code format (4–11 digits, decimals, check digit) but adds no new meaning beyond the schema, so baseline 3 is appropriate.

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?

Description clearly states the tool looks up complete tariffs and import regulations by Taiwan CCC code, using a specific verb (查) and resource (CCC code). It explicitly distinguishes itself from siblings by noting when to use lucky_ccc_predict (product name) and lucky_import_tax_estimate (amount calculation).

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 states '只知道商品名稱時先用 lucky_ccc_predict；要算實際金額用 lucky_import_tax_estimate', providing clear when-to-use and alternative guidance. It also anchors the data to the official search page, reinforcing appropriate use.

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