email_sendSend an email from an inbox you own. Costs 0.08 USDC, paid per-action via x402.
| Name | Required | Description | Default |
|---|---|---|---|
| to | Yes | Recipient email address | |
| body | Yes | ||
| html | No | ||
| payment | No | base64 x402 payment payload (X-PAYMENT); omit on first call to receive payment instructions | |
| subject | Yes | ||
| inbox_id | Yes | Inbox id returned by email_create_inbox |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the burden. It discloses the cost (0.08 USDC) and the payment mechanism (x402), which is valuable. However, it does not describe the two-step payment flow, return behavior, or any side effects beyond sending. This is a minimal but non-trivial disclosure.
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 fluff. Every word earns its place, conveying action, scope, and cost clearly.
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 has a complex payment flow (omitting payment on first call to receive instructions) that is not mentioned in the description. Without an output schema, the agent gets no guidance on what to expect in return. The description is too brief for a paid, multi-step operation with 6 parameters.
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 only 50%, with body, html, and subject lacking descriptions. The description adds no parameter-level details for these fields, and only indirectly clarifies inbox_id via 'an inbox you own.' It does not compensate for the missing schema descriptions, so parameter semantics are weak.
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 clearly states the verb ('Send'), the resource ('an email'), and adds a scoping constraint ('from an inbox you own'). This distinguishes it from email_create_temp and email_read_messages, and the ownership detail implies a prerequisite.
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 provides clear context: you must own an inbox and pay a fee via x402. It implies you need an inbox_id from email_create_inbox, but it does not explicitly list alternatives or when not to use this tool. It gives enough context for an agent to choose this over temp-inbox tools.
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.