PayPing: create coupon

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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=false and openWorldHint=true, so the safety profile is covered. The description still adds value by spelling out that this creates real data, requires user confirmation, and returns a generated code -- context not present in the 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?

Two sentences, zero filler, and the action plus its caution are front-loaded. Nothing repeats structure already encoded elsewhere.

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 return value need not be re-explained, and the description still highlights the returned code. The remaining gap is behavioral detail (e.g. whether the coupon is immediately live or how it interacts with product_codes), minor given the annotation coverage.

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 71%, and the schema already explains kind, amount, expires_on, coupon_code and product_codes. The description contributes nothing about any of the seven parameters, so the baseline 3 applies.

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?

States a specific verb and resource ("Create an active discount coupon") plus a notable side effect (returns its `code`), which is far more than a tautology. It is distinguishable from the get/list coupon siblings, though it never names 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?

Provides one real usage instruction -- confirm with the user first -- which is the right kind of guidance for a mutation. But it offers no when-not conditions, no prerequisites (e.g. do the referenced products need to exist?), and no routing to alternatives.

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