Ni Biashara Shelves — Africa FX data & services (x402)

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

With no annotations, the description carries the full burden. It discloses that it only creates a checkout and does not move money itself, and details the three outputs. It falls short of disclosing error handling or prerequisites, but the added behavioral context exceeds the schema's coverage.

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 with no wasted words. The main action is front-loaded, followed by the return values and a clarifying caveat. Every sentence adds essential information.

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 no output schema, the description effectively explains the return structure (three URLs) and the payment/claim flow. It covers the core mechanics clearly, but omits edge cases and error scenarios. The sibling tools cover adjacent operations, so this is adequately complete for a purchase action.

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 75% (pair, brief, and contact have descriptions; sku does not). The description does not add parameter-level detail, relying on the schema. The required 'sku' is inferable from the tool name and context, but it remains undocumented in both schema and description.

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 verb ('Creates') and resource ('a Coinbase checkout for one shelf'), and lists the concrete return URLs. It clearly distinguishes this purchase tool from siblings get_order and list_shelves, and the note that it 'Does not move money itself' further clarifies its role.

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?

It explains the intended usage flow by describing what to do with the returned URLs: pay with x402 client, human pay_url, and GET claim_url after paying. While it doesn't explicitly contrast with siblings, the checkout-creation purpose and the 'for one shelf' phrasing provide clear context for when to use it.

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. It discloses that delivery is included only after Coinbase reports payment COMPLETED, which is useful behavioral context. However, it doesn't mention any side effects, required permissions, or what happens if payment is not completed, leaving some gaps for a tool that likely involves a financial transaction.

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 that is efficient and front-loads the primary purpose. It includes a conditional detail that is relevant to the tool's behavior without unnecessary fluff. Slightly more structure could be added, but it's appropriately concise.

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 single-parameter tool with no output schema, the description covers the core purpose and a key behavioral condition. However, it lacks details on what the returned status looks like, error handling, or any prerequisites (e.g., must have an active order). Given the simplicity, it's adequate but not fully 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?

Schema description coverage is 0%, so the description must compensate. It mentions 'order_id' implicitly by referring to 'the order', but doesn't explain the format or any constraints beyond what the schema's type 'string' provides. The description adds minimal value for the single parameter, so a baseline 3 is appropriate given the low complexity.

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 verb ('Returns') and resource ('order status'), and adds a meaningful detail about when delivery is included. It distinguishes from siblings by focusing on order status rather than shelf operations, though it doesn't explicitly name alternatives.

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 usage for checking order status and collecting delivery after payment completion, but it doesn't explicitly state when to use this tool versus alternatives like buy_shelf or list_shelves. The context is clear enough for an agent to infer, but no exclusions or alternative routing are provided.

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 mentions 'Free to call' but does not describe the response format, error behavior, or potential side effects. The details about payment method are included but not explicitly tied to the response structure. Overall, key behavioral aspects like return type and failure modes are unspecified.

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 concise but somewhat disjointed. The first sentence describes shelf content, the second mixes payment details and 'Free to call'. It could be organized more clearly, separating the action from the content and metadata. Still, it is not excessively verbose.

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 that this is a list operation, the description lacks essential details such as the structure of the returned items, any filtering or pagination, and how the 'kind' parameter influences results. It also does not explain how the payment details relate to the shelf items. The tool is operational but leaves important contextual gaps.

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 input schema provides one parameter 'kind' with enum values, but the description gives no explanation of what this parameter does or how it affects the output. Without any textual guidance, the agent must infer its meaning solely from the enum values, which is insufficient. Parameter semantics are essentially absent.

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 indicates this tool lists shelves, containing African FX data and services, with pricing and payment details. The title reinforces the purpose. However, it could be more direct in stating the returned data structure, which is partially implied.

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 hints at usage via 'Free to call', implying it's a safe, read-only operation. It does not explicitly compare with sibling tools (buy_shelf, get_order), but the contrast is reasonably inferable from their names. More explicit guidance on when to prefer this over alternatives would strengthen this dimension.

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