phone_send_smsSend an SMS from a phone number you own. Costs 0.05 USDC, paid per-action via x402.
| Name | Required | Description | Default |
|---|---|---|---|
| to | Yes | Recipient number in E.164, e.g. '+15551234567' | |
| body | Yes | ||
| payment | No | base64 x402 payment payload (X-PAYMENT); omit on first call to receive payment instructions | |
| number_id | Yes | Phone number id returned by phone_buy_number |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden. It discloses a notable behavioral trait: the per-action cost (0.05 USDC) and payment mechanism (x402), plus the ownership requirement. However, it does not mention delivery status, rate limits, or other side effects.
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?
A single efficient sentence that front-loads the action, then adds cost information. Every word earns its place; no redundancy or filler.
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 description covers essential operational context: action, ownership prerequisite, cost, and payment method. However, it omits the two-step payment flow (first call omit payment) and return behavior, which are not covered by an output schema. Still, for a simple send tool, it is reasonably complete.
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 already provides descriptions for to, payment, and number_id with 75% coverage. The description adds semantic context for number_id by emphasizing ownership, but does not elaborate on body or payment behavior beyond what the schema states. Baseline of 3 is appropriate since schema covers most parameters.
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?
Description clearly states the action ('Send an SMS') and resource ('from a phone number you own'), immediately distinguishing it from sibling tools like phone_read_messages or phone_buy_number. The verb+resource construction is specific and unambiguous.
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 implies usage by naming the action, but does not explicitly explain when to use this tool over alternatives or mention prerequisites (e.g., needing a number_id from phone_buy_number). It lacks explicit when-not-to-use or alternative guidance.
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.
Each tool targets a distinct resource and action, clearly separated by domain prefixes (card_, email_, phone_, tiktok_). The only potential overlap is phone_read_messages vs wait_for_otp, but wait_for_otp is specifically for OTP extraction and is described as a replacement for hand-rolled polling, making the boundary clear. Status pollers are also domain-specific (card_status, tiktok_connect_status, tiktok_operation_status) and not ambiguous.
All tool names follow a consistent snake_case convention with domain-first prefixes (e.g., card_buy, email_send, tiktok_post, phone_temp_number). Even less common names like wait_for_otp and i402_plan are descriptive and stylistically consistent. There are no mixed conventions or vague verbs.
33 tools is above the typical 3-15 range, but the server covers a broad multi-domain purpose (cards, compute, domains, email, phone, TikTok, Twitter, orchestration). Each domain has a focused and coherent set, so the count feels justified rather than bloated. It is slightly high, but not excessively so.
Coverage is solid for email, phone, and TikTok, with full lifecycle operations (create, read, extend, delete/cancel where applicable). However, there are notable gaps: compute has only deploy (no list/stop/delete), domains have only check/register (no list/delete), and Twitter has only post (no read/manage). These gaps could force agents to work around missing resource management.