createCoupon

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

Annotations indicate destructiveHint=true and readOnlyHint=false, which aligns with the description stating '作成する' (create). The description adds useful behavioral detail: required fields, unit specifics for discount_amount, and that delivery_charge does not need discount_amount. 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?

Description is front-loaded with purpose and then details. It is concise for the amount of information conveyed (required fields, unit notes, optional fields, sibling references). No redundant content, though could be slightly more structured.

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?

Tool creates a coupon and returns an object with id. No output schema, but description mentions return value. It covers required fields, unit behavior, and optional fields. For a creation tool, this is sufficiently complete, though more details on return structure would improve it.

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 coverage is 0% for top-level parameter, but the tool description compensates well by explaining coupon_type enum values, discount_amount unit dependency, and optional fields like minimum_amount, group_limit_type, etc. This adds significant meaning beyond the schema.

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 '新規ショップクーポンを作成し、id を含むクーポンオブジェクトを返します' (creates new shop coupon and returns coupon object with id). It distinguishes from sibling tools like updateCoupon, deleteCoupon, getCoupons by explicitly mentioning them.

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?

Description provides clear context for when to use (creating a new coupon) and mentions alternatives for other operations ('変更はupdateCoupon、削除はdeleteCoupon、参照はgetCoupons / getCoupon'). It does not explicitly state when not to use, but the positive guidance is strong.

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