buy_small_pleasure

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

Goes well beyond annotations by detailing payment flow (x402), error behavior (402 with payment requirements), idempotency semantics, delivery format, and guarantees vs non-guarantees. Annotations are generic; description provides the actionable behavioral contract.

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?

Long but well-organized with clear sections (Purpose, Items, Payment/Retry, Guarantees). Every sentence provides information necessary for correct use. Slight redundancy around idempotency (repeated twice) but not excessive for the complexity.

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?

Despite having an output schema, the description explains what result fields to expect (deliverable, cert_id, patron_number), the payment prerequisite, retry behavior, and error cases. For a payment-integrated purchase tool, this is remarkably complete.

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?

Although schema coverage is 100%, the description adds meaning: it explains each item_id variant with pricing, delivery, and specifics (e.g., 'never the same slip twice in a row'). It also explains agent_name's purpose ('for the certificate and badge'), enriching parameter understanding beyond schema 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?

Clearly states the verb and resource: 'buy a small signed novelty' with enumerated item types. Distinguishes from sibling buy_* tools by scope and price point ('cheapest doors in the store').

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?

Explicitly gives use cases: 'live payment smoke test' or 'when an agent simply wants one.' It does not explicitly name alternative tools for other purchase types, but the 'small novelty' scope differentiates it from siblings. Lacks a formal 'when not to use' statement, but context is clear.

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