Reoon Email Verifier MCP by usefulapi

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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered structurally. The description's 'without verifying an email' usefully signals no credit is consumed, but it says nothing about what the response contains or whether limits reset.

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?

A single front-loaded sentence with no filler; every clause earns its place by naming the resource and the cost-free nature of the call.

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 zero-parameter, read-only, non-destructive call with full annotation coverage, the description is essentially sufficient. The only minor gap is that it doesn't hint at the shape of the returned credit figures (daily vs instant), though no output schema exists to cover that.

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 takes zero parameters, so the baseline of 4 applies. There is nothing for the description to disambiguate beyond confirming no input is needed, which the empty schema already shows.

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?

States a specific verb (Read) and resource (remaining daily and instant Reoon credits), and the clause 'without verifying an email' implicitly separates it from the sibling reoon_verify_email. It stops short of naming the alternative outright, so it lands just under a 5.

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?

Usage is implied rather than stated: an agent can infer this is the zero-cost way to check quota before spending credits on reoon_verify_email or reoon_create_bulk_verification. There is no explicit when/when-not framing or named alternative.

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?

Annotations already cover read-only, idempotent, and non-destructive traits, so the description focuses on what they cannot: results arrive in bounded pages, polling should be throttled, and very large exports are unavailable here and must be pulled from the Reoon dashboard. That export limitation is genuinely non-obvious and valuable.

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?

Four short sentences, purpose front-loaded, and each one adds distinct information (scope, exclusions, polling cadence, export fallback). No repetition of the title or annotations.

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?

There is no output schema, and the description says at a high level what comes back (task, progress, page of results) without enumerating result fields, which would help consumers. Annotations and the export caveat cover the rest, so it is close to complete.

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 0% — limit, offset, and task_id have no descriptions at all. The phrase 'a bounded page' hints at pagination but never explains limit caps (max 100), offset bounds (max 50000, default 0), or that task_id must be a numeric string, so the gap is left unaddressed.

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?

Names a specific verb (read) and three concrete resources: the bulk task, its progress, and a page of completed email results. It also explicitly disclaims starting new verification, which separates it from the sibling reoon_create_bulk_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?

States the negative case ('Does not start new verification') and gives polling guidance ('Wait between polls'), plus a fallback route for oversized exports (Reoon dashboard). It stops short of naming which sibling to use for other needs, but the context is clear.

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?

Goes well beyond the annotations: discloses that credits can be spent, that execution is asynchronous, that the job may continue even if the response is lost, and the mitigation (check the dashboard before resubmitting). These are exactly the non-idempotent, side-effecting traits an agent needs before calling a job-creating 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?

Four tight sentences, front-loaded with the core action and its credit cost, then the confirm gate, then the resubmission warning. No filler.

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?

With no output schema, the description partly compensates by pointing to reoon_bulk_results for results, but never states what the create call itself returns (e.g., a job identifier) and omits the `name` parameter. Otherwise complete for a credit-spending async job 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 0%, so the description carries weight: it explains the confirm:true gate (whose schema default false is otherwise unexplained) and the 10–1,000 email bounds. However, the `name` parameter is never mentioned, leaving one of three params undocumented in both schema and description.

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?

States a specific verb ('Submit'), resource (10–1,000 emails), and mode (asynchronous POWER verification), plus that it starts a vendor job. The closing sentence differentiates it from sibling reoon_bulk_results, which reads results rather than creating the job.

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?

Gives concrete operational guidance: requires confirm:true, check the dashboard before resubmitting, and results are retrieved via reoon_bulk_results. It does not explicitly contrast with the synchronous sibling reoon_verify_email, so the routing advice is clear but not complete.

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?

Annotations declare readOnlyHint=false and openWorldHint=true, so a side effect is expected, but the description adds concrete substance: it consumes Reoon credits, requires an explicit confirm flag, and has a parallelism/rate constraint. It also discloses a limitation on the result's meaning (no inbox existence, no delivery guarantee). The one gap is idempotency/non-idempotency rationale and whether a failed or cached check still burns credits.

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?

Four short sentences, each carrying a distinct constraint: scope, limitation, cost/prerequisite, rate limit, and alternative routing. The capability statement is front-loaded and nothing is repeated from the annotations.

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 two-parameter tool with no output schema and no annotations explaining results, the description covers cost, gating, limits, and what is not verified. It stops short of indicating the shape or meaning of a returned verdict (e.g., status vs. sub-signal breakdown), which an agent would need to interpret results without probing.

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 0%, so the description must carry the load, and it does for the non-obvious parameter by stating 'confirm:true is required' — without this the boolean would default to false and the call would silently not do what the agent intends. The email parameter is largely self-documenting via format/pattern/maxLength in the schema, so only minor value is missing.

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?

States a specific verb and resource ('Check email syntax, domain/MX and disposable-address signals') and scopes it to QUICK mode, which separates it from the bulk siblings named in the context. It also explicitly bounds the claim ('Does NOT verify inbox existence'), so an agent knows exactly what class of check this is.

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?

Explicit routing is given: 'Use bulk verification for lists' names the alternative and the condition that selects it (reoon_create_bulk_verification). It adds both a prerequisite ('confirm:true is required') and an operational exclusion ('Do not run continuously in more than five parallel requests').

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