email_validatorValidates email syntax and MX records. x402 payment required (Base mainnet USDC).
| Name | Required | Description | Default |
|---|---|---|---|
| emails | Yes | Email addresses to validate | |
| checkMx | No | Look up the domain's MX records (set false to only check syntax) | |
| payment | No | x402 payment payload (base64 JSON), signed EIP-712 exact/transferWithAuthorization. Omit on the first call — the tool will return payment requirements (accepts[]) as an error result. |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the full burden of behavioral disclosure. It states 'x402 payment required,' but fails to disclose the two-step flow (first call without payment returns accepts[] requirements), which is critical for successful invocation. It also omits return value expectations.
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 two sentences with no filler, and the core purpose is front-loaded before the payment caveat. Every word earns its place.
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 schema provides detailed parameter semantics, but no output schema exists and the description does not explain return values or the payment error flow. The payment parameter description partially compensates, but the top-level description is not fully complete for a tool with a non-obvious payment gate.
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 coverage is 100%, and each parameter has a description. The tool description doesn't add semantic detail beyond the schema, such as formatting or constraints, so baseline 3 is appropriate.
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 the specific verb 'validates' with a clear resource: 'email syntax and MX records.' This precisely identifies the tool's core function, leaving no ambiguity about what it does.
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 clearly implies the tool is for email address validation, and the payment note signals a precondition. There are no sibling tools, so no alternatives or when-not-to-use conditions are needed; however, no explicit usage context is provided.
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.
Only one tool exists, so there is no possibility of confusion with other tools. Its purpose is clearly distinct by default.
The single tool name 'email_validator' directly mirrors the server name and follows a clear snake_case convention. With only one tool, naming consistency is trivially maintained.
The server is extremely minimal with only one tool. While this feels thin, it aligns with the narrow purpose of email validation, making the count borderline but not inappropriate.
The tool covers both syntax validation and MX record checking, which are the core operations for the stated domain. No obvious missing functionality for a basic email validator.