Check up to 50 email addresses for deliverability in a single batch. Returns state and sub-state for each address.
Validate multiple email addresses for deliverability in a single batch. Returns an array of results with state and sub_state for each email. Maximum 50 emails per request.
| Name | Required | Description | Default |
|---|---|---|---|
| emails | Yes |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the full behavioral burden. It mentions the return shape ('state and sub_state'), which is helpful, but does not state whether this is a read-only operation, what happens when emails exceed 50, rate limits, or error behavior for invalid addresses. Significant gaps remain for a validation tool with no structured safety hints.
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?
Three short, information-dense sentences. The purpose is front-loaded, followed by output structure and a key constraint. No wasted words.
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?
For a simple batch validation tool with no output schema, the description covers the core operation and return shape, but omits error handling, rate limits, and when to prefer sibling tools. It is adequate but leaves clear gaps that could affect correct invocation.
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?
With 0% schema description coverage, the description must compensate. It states the parameter accepts multiple emails and enforces a maximum of 50, which matches the schema's maxItems, but does not explain the email format or what happens if fewer than 1 is provided (minItems). Nonetheless, the description provides meaningful constraint info beyond the bare schema.
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 a specific verb ('Validate') and resource ('email addresses for deliverability'), and the batch nature distinguishes it from likely sibling validate_email. It also clarifies the output structure ('array of results with state and sub_state').
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?
No guidance on when to use this tool versus validate_email or check_account. The batch limitation (max 50) is stated, but that's a constraint, not usage context. There are no exclusions or alternative suggestions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.