BlinkCodes catalog

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

No annotations are provided, so the description carries the full burden — and it does substantial work: it discloses the two-phase charging behavior ('nothing is charged' on the first call), the payment rail (USDC on Base x402), that no account/browser is needed, and the email delivery path. What's missing for a payment tool is edge-case behavior: order expiry, what happens if the second call fails, idempotency/retry semantics, and refunds. Strong but not exhaustive.

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?

Purport, payment contract, and two-call flow each get exactly one sentence, with the most critical operational constraint (the two-call sequence) front-loaded before the settle step. Every sentence earns its place; there is zero filler or restatement of the name.

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?

This is a complex tool — 9 parameters, a two-call payment protocol, and no output schema — and the description covers purpose, payment rail, phase split, and delivery without assuming external knowledge. Minor gaps remain for a payment flow: the shape of the returned payment requirements, failure/expiry behavior, and what the first call returns beyond order_id (partially implied). These are secondary given the strong schema support, but a fully complete definition would address them.

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 100%, so every parameter is already documented individually, including cross-references to get_product's requires_amount/requires_account and search_catalog's product_id. The description adds genuine value beyond the schema by partitioning parameters across the two call phases (items like email, amount, product_id on call one; order_id and payment_payload on call two) and by clarifying the amount-vs-item_id exclusivity. This exceeds the baseline 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 names a specific verb (buy) and distinct resources (gift card, service top-up, travel eSIM) plus the delivery outcome, and situates the payment contract (USDC on Base/x402). It clearly separates this from siblings: get_product and search_catalog are discovery/requirements tools, while this one settles a purchase. An agent can distinguish it without opening any schema.

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 gives an explicit two-call procedure — first with order arguments to obtain payment requirements and an order_id (nothing charged), then with the order_id plus the signed x402 payload to settle. This is strong context for how to drive the tool. However, it never names alternatives or states when NOT to use it (e.g., 'use search_catalog/get_product first to determine requirements'), leaving sibling routing implicit rather than explicit.

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

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

No annotations are provided, so the description carries the full burden. It discloses the return content (denominations, inputs, country restrictions), which is useful, but it does not explicitly state that the operation is read-only, nor does it describe error behavior or side effects. For a simple getter, this is adequate but not thorough.

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 a single sentence with no wasted words. It leads with the core action and resource, then enumerates the returned data in a compact clause. Every word earns its place.

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?

Given the tool's simplicity (one parameter, no output schema, no annotations), the description provides sufficient context by enumerating the key return categories. It does not address missing-ID scenarios or error cases, but these are standard for a get-by-id operation and not critical for the described scope.

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?

The schema already provides 100% coverage for the single parameter 'id' and explains its origin ('from search_catalog'). The description only repeats the 'by id' concept, adding no new semantics beyond what the schema offers. 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?

The description uses a specific verb ('Get') and resource ('catalog product') with an explicit identifier ('by id'). It clearly distinguishes from the sibling search_catalog by targeting a single product and lists the key data included (denominations, required inputs, restricted countries).

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?

Usage is implied: this tool is for retrieving a specific product by its ID, so it would be used after obtaining an ID from search_catalog. However, it does not explicitly mention when to use this instead of alternatives or offer any when-not guidance, so the guidance is indirect.

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

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 clearly states the operation is a search ('Search the store catalog') and describes the expected output ('Returns matching products with their price, availability and product page URL'). This transparently conveys a read-only behavior, though it does not mention any edge cases like rate limits or pagination.

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 a tight two-sentence summary that leads with the action and clearly states the return value. No filler or redundant information is present.

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?

The description effectively covers the tool's purpose and return content, which is especially useful given the lack of an output schema. It is adequate for a simple search tool, though it could benefit from a note on how it relates to the sibling 'get_product' tool.

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 all four parameters (type, limit, query, country) are already fully documented in the input schema. The description adds no additional meaning to the parameters, as it only indirectly references product types ('gift cards, service top-ups, eSIM') which correspond to the 'type' enum.

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 identifies the tool as a catalog search for specific product types (gift cards, top-ups, eSIM) and states it returns matching products with price, availability, and URL. This distinguishes it from the sibling 'get_product' which likely fetches a single product's details.

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 implies that this tool is for searching the catalog to find matching products, but it does not provide explicit guidance on when to choose it over the sibling 'get_product' tool. No exclusions or alternative scenarios are mentioned, so usage context is clear but not differentiated.

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