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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, so the safety profile is fully covered and the description isn't required to restate it. It adds genuine value beyond annotations by disclosing content provenance (取自好運器官方指南與現行試算規則), helping the agent judge authority/reliability of the answer.

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 sentences, front-loaded with the topic scope and followed by example queries; no filler. The topic list is dense but each item is a discrete subject area that earns its place.

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?

An output schema exists, so the description needn't explain return values, and it correctly focuses on scope and coverage instead. Combined with the zero-param schema and read-only annotations, an agent has everything needed to select and call it; only explicit sibling routing is missing.

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?

The tool takes zero parameters, so per the guidelines the baseline is 4. There is nothing parameter-related for the description to compensate for, and the description correctly spends no space on inputs.

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 names a specific verb+resource (取得 台灣快遞貨物進口的簡易申報規定) and then enumerates the exact topics covered — C1/C2/C3, EZ WAY, NT$2,000 免稅, 6 次限制, 營業稅 5%. An agent can tell this is a Taiwan import-declaration knowledge tool, clearly distinct from siblings like lucky_import_tax_estimate or lucky_ccc_tariff_lookup.

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 gives concrete usage context via example questions ('多少錢要繳稅／什麼是簡易申報／EZWay 是什麼／C1 C2 C3 差在哪'), which tells the agent the kind of query this answers. It stops short of explicitly naming alternatives (e.g., when to prefer lucky_import_tax_estimate for a numeric estimate), so it's strong but not fully routing.

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