list_custom_fields

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

No annotations are provided, so the description carries the full burden. It discloses the API endpoint (GET /v1/custom_fields) and the return structure (dict with total and fields array, each field containing id, name, type, options). This is sufficient for a read-only operation with no side effects.

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 well-structured with distinct sections for purpose, usage, API call, and return structure. It is concise, using only necessary information without redundancy. Every sentence adds value.

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 tool with no parameters and no output schema, the description covers all essential aspects: purpose, usage context, API endpoint, and return format. It provides enough information for an agent to use the tool correctly without additional context.

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 input schema has zero parameters, so schema coverage is 100%. According to guidelines, 0 parameters yields a baseline score of 4. The description adds no parameter details, but none are needed.

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 clearly states the tool's purpose: retrieving the list of customer custom fields defined by the store. The verb '取得' (retrieve) and resource '客戶自訂欄位清單' (customer custom field list) are specific. While sibling tools include many 'list' tools, this one is uniquely about custom fields, distinguishing it from others.

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 description includes a usage section explaining when to use the tool (e.g., to view additional custom fields like birthday, preferences, notes) and its purpose in understanding customer data structure or completeness. It does not explicitly state when not to use it or mention alternatives, but the context is clear.

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