create_topup_linkCreate a Stripe Checkout URL that a human opens to fund the wallet. Amount between 100 and 100000 cents USD.
| Name | Required | Description | Default |
|---|---|---|---|
| key | No | Agent key (agp_…). Optional when the MCP connection sends Authorization: Bearer. | |
| amountCents | Yes | Top-up amount in USD cents, e.g. 2000 = $20 |
Changes observed during successful MCP inspections.
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 the action creates a Stripe Checkout URL, requires human action, and enforces an amount range of 100–100000 cents. It does not state auth requirements, URL expiry, or return format, but the core behavior is reasonably transparent for a simple creation tool.
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, front-loaded sentence with no filler. It conveys the action, the payment provider, the user's role, and the amount constraint efficiently.
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 low-complexity tool with no output schema, the description covers the key facts an agent needs: what is created, who uses it, and the valid amount range. It could explicitly state that the URL is returned, but 'Create a ... URL' strongly implies that outcome, so the gap is minor.
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%, but the description adds meaningful constraints beyond the schema by specifying an exact allowed amount range (100–100000 cents) and clarifying the purpose of the amount. The schema only gives broad integer limits, so the description materially improves parameter understanding.
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 ('Create a Stripe Checkout URL') tied to a clear resource (funding the wallet). It also adds the payment mechanism and currency, making the tool's role unambiguous and distinguishing it from siblings like pay_service or spend.
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 clearly conveys when to use the tool: when a human needs a checkout link to fund the wallet. It does not explicitly mention alternatives or say when not to use it, but the intended context is evident from the wording.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.