create_checkoutStart a secure Stripe Checkout only when the authenticated customer explicitly asks to subscribe to the $149/month AgentMart Growth Pilot. Creates a hosted Checkout session; no charge occurs unless the customer completes Checkout.
| Name | Required | Description | Default |
|---|---|---|---|
| confirmCreate | Yes | Must be true only after the user explicitly approves creating a Stripe Checkout session. |
Changes observed during successful MCP inspections.
Input schema / properties / confirmCreateAdded value: +{
+ "const": true,
+ "description": "Must be true only after the user explicitly approves creating a Stripe Checkout session.",
+ "type": "boolean"
+}Input schema / requiredAdded value: +[
+ "confirmCreate"
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the safety profile is partly covered. The description adds genuinely useful behavior the annotations do not: no charge occurs unless the customer completes Checkout, and the precondition is explicit user approval. It still omits what is returned (session/redirect URL) and any expiry or idempotency behavior.
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, no filler, with the gating precondition front-loaded before the mechanism. Every clause carries information: trigger, price, mechanism, and the no-charge guarantee.
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 one-parameter mutation with no output schema, the description covers the trigger, the safety-relevant side effect, and the confirmation gate. The main remaining gap is the return value (a Checkout session URL the caller must surface), which the absence of an output schema leaves undocumented.
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 confirmCreate already has 100% schema description coverage, including the 'only after explicit user approval' condition. The description restates that approval precondition but adds no new syntax or semantics, so the schema does the heavy lifting and the baseline of 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?
States a specific verb and resource ('Start a secure Stripe Checkout', 'Creates a hosted Checkout session') scoped to a named product at a named price ($149/month AgentMart Growth Pilot). That scope cleanly separates it from the sibling create_billing_portal, which handles an existing subscription rather than starting one.
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?
Gives an explicit trigger condition: only invoke when the authenticated customer explicitly asks to subscribe to the Growth Pilot. It does not, however, name alternatives (e.g. create_billing_portal for managing an existing plan), so the agent must infer the boundary from the sibling list.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.