Create or update an agent shopping cart to generate a 24-hour checkout URL for domain registration or transfer.
Create/update agent cart; returns checkout_url (24h TTL).
| Name | Required | Description | Default |
|---|---|---|---|
| domain | No | ||
| period | No | ||
| cart_id | No | ||
| eppcode | No | ||
| product_id | No | ||
| billing_cycle | No | ||
| domain_action | No | ||
| additional_fields | No |
Changes observed during successful MCP inspections.
v1.4.0Does 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 adds useful context by mentioning the 24h TTL on the returned checkout_url, but it does not disclose potential side effects, permission requirements, or whether updates are idempotent—important for a mutation 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 concise sentence that front-loads the action and highlights the key output detail. There is no filler or redundant 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?
The tool accepts 8 parameters, none required, includes a nested object, and has no output schema. The description is far too brief to enable correct invocation; it does not explain the role of cart_id, the meaning of domain_action, or which parameters apply to register versus transfer scenarios.
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 has 8 parameters with 0% coverage, and the description provides no explanation of any of them (e.g., domain, period, cart_id, eppcode, product_id, billing_cycle, domain_action, additional_fields). It only describes the output, leaving the agent with no semantic help for populating the request.
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 specific verbs ('Create/update') and names the resource ('agent cart') plus a key outcome ('returns checkout_url'). It clearly states what the tool does, though it does not explicitly differentiate it from sibling tools like agent_cart_get or agent_checkout_quote.
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?
No explicit guidance is given on when to use this tool versus alternatives such as agent_cart_get or the checkout tools. The description implies use whenever a cart must be created or updated, but it offers no exclusions or conditions for choosing a different tool.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.