Tlacuilo

email_validate

email_validate

Read-only

Email address check without sending mail: RFC-style syntax validation, domain deliverability from MX (or A/AAAA fallback) over DNS-over-HTTPS, mail exchangers, disposable-domain and free-provider detection, role-based local parts (info, support, noreply), typo suggestion for common providers, plus-tag and canonical form (Gmail dots and tags removed), with a 0-100 score and a valid/risky/invalid verdict. Price: $0.002 USDC per call (x402).

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "email": "<email>"
    },
    "name": "email_validate"
  }
}

Input Schema

Name	Required	Description	Default
`email`	Yes	Email address to check

Schema Changelog

Changes observed during successful MCP inspections.

First observedNov 15, 2026

TDQS

A4/5.0

Behavior4/5

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

Annotations only declare readOnlyHint=true, and the description goes well beyond that: it discloses that live DNS-over-HTTPS lookups occur (MX with A/AAAA fallback), that no mail is sent, and — critically — that each call costs $0.002 USDC via x402. Cost and external-network behavior are exactly the traits an agent needs before invoking. It stops short of describing latency, failure modes, or caching, so not a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The key differentiator ('without sending mail') is front-loaded and the rest is a compact feature inventory in one sentence. It is dense and slightly list-like, but every clause names a real capability or the price, so little is wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a one-parameter, read-only tool with no output schema, the description supplies both the output shape (0-100 score plus valid/risky/invalid verdict) and the commercial cost model. Nothing an agent needs to decide to call it or interpret the result is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

There is a single required parameter with 100% schema description coverage ('Email address to check'), so the schema already carries the semantics. The description implies what the address is subjected to but adds no format, normalization, or edge-case guidance for the input itself.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb+resource ('Email address check') and immediately delimits scope with 'without sending mail', then enumerates exactly which checks are performed. An agent knows precisely what this tool returns conceptually (syntax, DNS/MX deliverability, disposable/free detection, role accounts, typo hints, canonicalization) without opening anything else.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The phrase 'without sending mail' implicitly tells the agent this is a non-delivery verification step, which is useful context, but there is no explicit when-to-use/when-not framing and no named alternative among the sibling tools. Usage is inferable rather than stated.

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

All Tlacuilo tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources

Need Help?