list_coupons

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

Annotations already set readOnlyHint=true, so the read-only nature is disclosed. The description adds that it shows specific fields and usage stats, but no additional behavioral traits (e.g., pagination behavior, rate limits) are mentioned. With annotations covering the safety profile, this is adequate but not enhanced.

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 two concise sentences, front-loaded with the primary action. It includes essential return fields and a helpful hint about the fields parameter without any filler or redundant 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?

For a simple read-only list tool with 4 optional parameters covered in the schema and no output schema, the description is complete. It explains what the tool does, what data is returned, and how to tailor the response. There are no missing critical details given the tool's simplicity.

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 100% for all 4 parameters (page, fields, search, per_page). The description only mentions the 'fields' parameter, which is already fully described in the schema. Therefore, the description adds little semantic value beyond the schema, matching the baseline of 3.

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 'List discount coupons' with a specific verb and resource. It distinguishes itself from sibling tools like get_coupon, create_coupon, and delete_coupon by focusing on listing. It also specifies the key fields returned (code, type, amount, usage stats), making the purpose unambiguous.

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 makes it clear this is for listing coupons, which is the appropriate use case versus get_coupon for a single coupon. It provides usage advice for the 'fields' parameter ('request only needed fields'). However, it does not explicitly mention alternatives or when not to use this tool, though the sibling list provides context.

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