verify_emailVerify a single email address — syntax, domain/MX, disposable + role detection, typo suggestion, and mailbox reachability. Returns a deliverability verdict (deliverable / risky / undeliverable / unknown). Consumes 1 credit.
| Name | Required | Description | Default |
|---|---|---|---|
| Yes | The email address to verify. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations don't provide readOnly/destructive guarantees; description adds important behavioral context: consumes 1 credit and returns a deliverability verdict. This goes beyond what annotations and schema convey.
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?
Two sentences, front-loaded with action and resource, and every word adds value. No filler or redundancy.
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?
Covers purpose, scope, return value, and cost. Missing edge-case handling details but is adequate for a single-parameter tool. No output schema exists, so describing the verdict is useful.
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 covers the only parameter (email) completely. The tool description adds no extra detail about parameter syntax or formatting, so the baseline of 3 applies.
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?
Clearly states 'Verify a single email address' and enumerates specific components (syntax, domain/MX, disposable, role, typo, mailbox reachability), distinguishing it from narrower siblings like check_disposable or check_typo.
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 indicates it verifies a single email address but does not explicitly state when to use this tool over alternatives like check_disposable or verify_emails. Usage context is implied, not explicit.
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 function: single verification, synchronous batch, asynchronous bulk list, plus separate diagnostic checks (disposable, typo, domain, blacklist, header, SMTP code). The three verify tools are clearly differentiated by single vs. batch, sync vs. async, and size limits.
All tool names follow a consistent verb_noun pattern in snake_case: check_*, get_*, verify_*, generate_*, analyze_*, lookup_*. The batch variations (verify_emails, verify_list) are predictable extensions of verify_email.
12 tools is well within the ideal range for a focused email verification service. Each tool serves a clear purpose covering verification, diagnostics, DNS generation, and account management without unnecessary bulk.
The domain is well-covered: single/batch/large-list verification, common pre-check diagnostics, blacklist lookup, DNS record generation, and SMTP code explanations. Minor gaps include no history listing or batch job management beyond polling, but these are not core to the stated purpose.