kfc_promotion

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses that an unknown or expired code returns a 404 rather than a null success payload, which is valuable error-handling context. It also explains what additional data a serialized-code lookup returns (usage metadata fields). It doesn't mention rate limits or auth, but for a simple lookup tool the disclosed behaviors are substantial.

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 dense but well-structured: it states the core function first, then explains the two code types, the exclusivity requirement, the extra metadata for serialized lookups, and the error behavior. Every sentence adds information; no filler or repetition.

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 two-parameter lookup tool with no output schema, the description covers the input requirements, the distinction between the two lookup modes, the extra metadata returned for one mode, and the error behavior. It doesn't describe the full promotion object structure, but without an output schema that's a minor gap; the essential information for calling the tool correctly is present.

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%, so the schema already documents both parameters. The description adds meaning by explaining the real-world context of each code type (customer checkout vs. per-print QR/serial code) and the relationship between them (serialized code resolves to a shared redemption code). This goes beyond the schema's descriptions.

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 looks up one KFC promotion by redemption code or serialized code, with a specific verb ('Look up') and resource ('KFC promotion'). It distinguishes between the two code types and explains the difference between redemption codes and serialized codes, which differentiates it from sibling tools like kfc_promotions (plural) and kfc_menu.

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 explicitly states that exactly one of code or serialized_code is required, and explains when each should be used: redemption code for customer checkout codes, serialized code for per-print QR/serial codes. It also notes the additional usage metadata returned for serialized-code lookups, giving clear context for choosing between the two parameters.

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