Email Verification MCP

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

With no annotations provided, the description bears full burden for behavioral disclosure. It reveals that the tool is paid, details the cost and payment flow (including 402 handling with Solana memo and re-call with payment_tx), and outlines scoring criteria and return structure (ranked array, grade distribution, average score). It does not mention rate limits or destructive actions, but these are less critical for a scoring tool.

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 well-structured and efficient, front-loading the core purpose and then detailing scoring, payment, and parameters. It is slightly lengthy due to the payment details but remains focused and free of redundancy. Every sentence adds value.

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?

Given the three parameters and the complexity of the payment flow, the description is complete. It covers purpose, usage, payment, parameters, and return values. The only minor omission is the exact free-tier allowance limit, but the context of 'daily free allowance' is sufficient. No output schema is provided, but the description summarizes return structure adequately.

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 100%, so the baseline is 3. The description adds marginal value beyond the schema by explaining the payment context for payment_tx and the free-tier scoping for agent_id, but these are implicit in the schema descriptions. The bulk of parameter semantics is already covered in the 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 clearly states the tool's function: scoring a batch of B2B leads, ranking them best-first, with scores 0-100 (A-F) based on email deliverability and domain credibility. It differentiates from siblings like lead_quality_score by emphasizing it as the 'volume play' for prioritizing prospect lists, and from verify tools by focusing on scoring rather than verification.

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 explicitly describes when to use this tool ('volume play for prioritizing a prospect list') and includes key usage constraints: up to 100 leads per call and a payment model. However, it does not explicitly state when not to use it or suggest alternatives for single-lead scoring, which is a minor gap.

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

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

No annotations are provided, so the description carries full burden. It discloses payment cost and flow, caching and deduplication behavior, result structure (per-email array plus summary), and authentication bypass option. This is thorough and trustworthy.

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 well-structured: first paragraph covers core functionality and caching, second covers payment. It is concise with no waste; every sentence adds value.

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?

Despite the output schema documenting return values, the description covers usage limits, caching, payment, and distinguishes from siblings. It is fully self-contained and leaves no major questions about the tool's operation.

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?

Although schema coverage is 100%, the description adds critical context beyond the schema: it explains the impact of domain caching on costs, the purpose of payment_tx in retry flows, and the agent_id's role in free-tier counting. This greatly enhances parameter understanding.

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 tool's function: 'Verify an array of email addresses in one call' for list hygiene and bulk lead enrichment. It distinguishes itself from sibling 'verify_email' by emphasizing volume and caching benefits for repeat domains.

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 usage context: max 100 emails per call, caching behavior, and payment instructions including 402 handling. However, it does not explicitly state when NOT to use it (e.g., for single emails), though the sibling context implies it.

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

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

With no annotations, the description carries the full burden. It discloses that the tool is paid ($0.50 USDC), defaults to today UTC, returns structured JSON, includes a payment re-call flow on 402, and mentions an auth bypass. This is adequate behavioral context, though it omits rate limits or other constraints.

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 concise and well-structured, with the core purpose in the first sentence. It uses only 5 sentences, each adding necessary information without redundancy. Every sentence 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?

Given the complexity of payment handling and the existence of an output schema, the description covers purpose, return format, payment, and error recovery. It does not detail the output schema structure or potential errors beyond 402, but the output schema exists to compensate. Overall, it is sufficiently complete for a sample tool.

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 100%, so baseline is 3. The description adds meaning for 'payment_tx' (explains usage after 402) and 'agent_id' (scopes free-tier counter), going beyond the schema. The 'date' parameter is not elaborated, but the schema already describes its format and default.

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 tool retrieves the top 5 signals from today's brief as structured JSON, explicitly distinguishing it from the sibling tool 'daily_brief' by noting it is a cheap sample. The verb 'Get' and resource 'top 5 signals' are specific and unambiguous.

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 for when to use the tool e.g., to decide whether to buy the full brief, and details payment handling. However, it does not explicitly state when not to use it or compare to other siblings beyond daily_brief.

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

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

With no annotations provided, the description carries full burden. It discloses payment requirement, default date behavior, expiration, and re-call logic. It does not mention rate limits or side effects, but the disclosed behavioral aspects (especially the payment flow and provenance attestation) are substantial and add value beyond what annotations might cover.

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 well-structured paragraphs: first states purpose and contents, second details payment and expiration. Every sentence contributes necessary information with no redundancy or ambiguity.

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?

Given an output schema exists, the description correctly avoids explaining return format. It covers purpose, payment, expiration, and attestation. A minor gap is the lack of explicit mention that the output contains the listed data, but that is implied and supplemented by the output schema.

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%, but the description adds deeper meaning: date defaults to today UTC, payment_tx is for 402 re-calls, stripe_token is an alternative payment method, and agent_id scopes the free-tier counter. This goes beyond the schema descriptions, providing practical usage context.

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 ('Get') and defines the resource ('curated daily email-verification brief') with enumerated contents (volume, deliverability mix, etc.). It distinguishes from sibling 'brief_summary' by emphasizing this is a full daily package with provenance attestation.

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 explicit context for payment flow ($5 USDC, 402 handling, payment_tx parameter, fnet_ bypass) and expiration behavior. However, it does not explicitly state when to use this tool over siblings like 'verify_email' or 'batch_verify', leaving the distinction implied.

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

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

With no annotations, the description carries the full burden. It discloses the scoring components (deliverable validity, disposable detection, domain age, etc.), the grading system, and the payment retry behavior on 402. It could be more specific about failure modes, but overall it is transparent.

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 fairly concise with two paragraphs. The first paragraph clearly explains the tool's purpose and inputs. The second paragraph on payment is necessary but slightly verbose. Overall, it is well-structured and front-loaded.

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 description covers the main aspects: scoring components, output (including recommendation), payment details, and retry mechanism. The output schema is present, so detailed return values are separated. It does not compare to siblings but is adequate for the tool's complexity.

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 100%, so baseline is 3. The description adds context for payment_tx (retry on 402) and agent_id (free-tier scoping), providing value beyond the schema definitions. The email and domain parameters are adequately explained in context.

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 tool scores a B2B lead 0-100 (grade A-F) based on email deliverability and domain credibility. It explains the combination of signals and output includes a score and recommendation. However, it does not explicitly differentiate from sibling tools like batch_lead_score or verify_email, which could cause confusion.

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 implies usage for deciding whether a lead is worth outreach time and mentions payment conditions. However, it does not provide explicit guidance on when not to use this tool versus alternatives like verify_email or batch_lead_score, leaving the agent to infer.

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

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It indicates the tool is free and provides informational content, but does not explicitly state whether it is read-only, has side effects, or any other behavioral traits beyond the high-level purpose.

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 sentence that is somewhat dense and run-on, mixing two distinct topics (protocol details and attestation how-to). It is not overly long but could be more structured and front-loaded.

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?

Given the tool has no parameters and an output schema exists (not shown), the description provides a reasonable overview of the content. However, it does not fully clarify the tool's exact return format or guarantee completeness for an agent to understand the full scope.

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?

The tool has no parameters, so the baseline is 4. The description adds context about the content (network details, attestation process) that helps understanding what the tool returns, even though no parameters exist to document.

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 tool provides details about the FoundryNet Data Network and MINT Protocol, and explains how to attest email/contact verification on-chain. It distinguishes itself from sibling tools like batch_lead_score and verify_email by focusing on informational content rather than scoring or verification actions. However, the verb is implicit (e.g., 'details' implies retrieval) rather than explicit.

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 mentions 'sibling data servers available across the network' but does not provide explicit guidance on when to use this tool versus alternatives. No when-not-to-use conditions or prerequisites are stated.

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

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

No annotations are provided, but the description fully discloses all behavioral traits: paid nature, daily free allowance, 7-day caching of domain facts, return fields including 'best-effort smtp_check', and payment flow for 402 errors. No contradictions.

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 five sentences, front-loaded with purpose and return fields, followed by payment details. Every sentence adds value, no fluff.

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 description is complete given the presence of an output schema (not shown but stated): covers return values, caching, payment, and parameter roles. No obvious missing information for such a tool.

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%, but the description adds context beyond the schema: explains 'agent_id' scopes the free counter and 'payment_tx' is for re-calling after 402. This significantly aids correct parameter usage.

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 'verify' and the resource 'single email address', with explicit use cases (lead enrichment, signup gating, list hygiene). It distinguishes from sibling tools like 'batch_verify' and 'lead_quality_score'.

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 explicit guidance on when to use (single email verification), payment details including free allowance, and re-call flow on 402. It implies batch use should go to 'batch_verify'.

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