PayPing: coupon detail

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds only a partial inventory of returned fields, which the output schema already carries, and says nothing about behavior on an unknown code or rate limits.

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?

A single dense sentence with the resource and lookup key front-loaded and zero filler. It is telegraphic rather than a complete sentence, but nothing in it is wasted.

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 one-required-parameter read tool with an output schema and full annotations, the essential selection information is present. The only real gap is what happens when the code does not match a coupon, which is minor for this tool shape.

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 coverage is 0% for the single 'code' parameter, so the description must compensate. 'By code' does establish that the parameter is the coupon's lookup identifier, but it adds no format, length, or case-sensitivity guidance beyond what the schema's string type implies.

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 states a specific resource and lookup key ('One coupon by code'), making it distinguishable from payping_list_coupons without opening either schema. It never uses an explicit verb like 'retrieve', but the intent is 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?

There is no when-to-use guidance, no routing to the sibling payping_list_coupons, and no prerequisites (e.g., a valid/known code, case sensitivity). Only the weakest implication exists that this is for looking up a coupon you already have a code for.

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