sms_order

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

No annotations are provided, so the description carries full burden. It discloses payment (3 USDC on Base via x402), which is valuable behavioral context. However, it omits critical details: whether the call is synchronous, what happens if no SMS arrives, refund/reversal policy, how confirmNewPurchase affects behavior, or any rate limits.

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 that states the action, outcome, and cost with no wasted words.

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 paid mutation tool with no annotations and no output schema, the description is insufficient. It should explain the rental lifecycle (e.g., what to do after receiving the code, how to cancel via sms_cancel, how to poll via sms_status) and the role of confirmNewPurchase to prevent accidental duplicate purchases.

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 100%, so all three parameters (country, service, confirmNewPurchase) are already documented in the schema. The description adds no additional parameter semantics, which is the baseline expectation when the schema does the work.

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 and resource: 'Rent a phone number for SMS verification and receive the code.' This is clear, but it does not differentiate from siblings like sms_rental_order or sms_quote, leaving the agent to infer which SMS tool to pick.

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 when-to-use guidance or alternatives are provided. The description implies this is the ordering step but doesn't mention prerequisites such as checking sms_quote or sms_pricing first, nor does it say when to prefer this over sms_rental_order or other SMS tools.

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