buy_creditsPurchase additional hosted checks via a Stripe Checkout link. Each 10,000-check pack costs $9, and credits never expire; payment confirmation adds credits to your key.
Get a Stripe Checkout link for more hosted checks: 9 USD per 10,000, one payment, credits never expire. Open the link to pay; credits land on the key when Stripe confirms.
| Name | Required | Description | Default |
|---|---|---|---|
| packs | No | How many packs of 10,000 (default 1) |
Changes observed during successful MCP inspections.
v0.2.4Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations mark readOnlyHint=false (write operation) and openWorldHint=true (external effects). The description discloses the external Stripe payment flow and the delayed credit delivery upon confirmation, which adds valuable context beyond the annotations. It does not cover failure scenarios or refunds, but it adequately explains the primary side effect.
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 concise sentences, no fluff. The action is stated first, followed by the commercial details and the payment-confirmation flow. Every clause contributes to the agent's understanding of how to invoke the tool and what to expect.
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 simple one-parameter tool with no output schema and annotations covering safety, the description is nearly complete. It explains the action, pricing, and the confirmation mechanism. It stops short of explicitly stating the return value (the checkout URL) and handling failures, but these are minor gaps given the simplicity.
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 single parameter 'packs' is fully described in the schema (coverage 100%), with default and range. The description adds the cost per pack ($9 per 10,000) and clarifies that a payment is one-time and credits never expire, giving the agent useful pricing context to help with user requests. This exceeds the baseline.
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 action ('Get a Stripe Checkout link'), the resource (hosted checks credits), and even key commercial terms. It is clearly distinct from siblings like signup, verify_email, verify_batch, and balance, which deal with identity and account state rather than purchasing.
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 implicitly communicates when to use this tool: when the user needs more hosted-check credits. It doesn't explicitly contrast with alternatives, but the tool's purpose is self-evident given sibling names, and the description includes the cost per pack and the payment flow, which clarifies its role.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.