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

Discloses quota consumption and error condition (400 if domain not verified), adding value beyond annotations that indicate destructiveHint and idempotentHint. Does not mention idempotency behavior when mailbox already exists.

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 efficient sentences covering purpose, behavior, and usage guidance without 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?

Covers purpose, usage boundaries, behavioral consequences, and parameter prerequisites. Lacks mention of return value or error handling for duplicate mailbox creation, but overall sufficient for a creation 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 has 100% coverage, but the description adds practical context about domain validation and quota impact, helping the agent understand parameter implications beyond schema definitions.

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 'Create a new mailbox' and specifies the resource and action. Explicitly distinguishes from lookup tools with 'do NOT call this just to look one up.'

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?

Provides explicit when to use ('when the user explicitly asks to create/add/make a mailbox') and when not to ('do NOT call this just to look one up'). Also mentions prerequisite condition for custom domains requiring DNS verification.

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 provide destructiveHint and idempotentHint, but the description adds value by explaining the silent success behavior on already-revoked endpoints, aiding agent understanding of retry safety.

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 verb and resource, no unnecessary words. Every sentence provides essential information.

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 simplicity of the tool (one parameter, no output schema), the description covers idempotency and safety. It could elaborate on the effect of revocation (e.g., stops sending events), but is sufficient for a straightforward 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?

Schema coverage is 100% with a clear description for 'id' ('Webhook endpoint UUID.'). The description does not add further semantic information beyond what the schema already provides.

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 the specific verb 'Revoke' and resource 'webhook endpoint by id', clearly distinguishing it from siblings like register_webhook (create) and list_webhooks (list).

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 states idempotency and safe retries ('already-revoked endpoints succeed silently so retries are safe'), providing clear guidance on when to use and re-use the tool, but does not explicitly mention alternatives.

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?

Beyond annotations (readOnlyHint, openWorldHint), description discloses inline payload cap at 5 MiB and the return format { tooLarge: true, sizeBytes } when exceeded. No contradiction with annotations.

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 sentences: first states purpose, second gives usage context, third details limit. No extraneous words. Front-loaded with key action.

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 2-param tool with no output schema, the description covers purpose, usage, behavioral constraint, and output format for edge case. Fully sufficient.

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% with descriptions for emailId and index. Description adds little beyond schema, but context of using after qmailing_get_email adds value. Baseline 3 is appropriate.

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?

Description states 'Download an attachment from an email and return its bytes as base64' – specific verb+resource+output. Distinguishes from sibling qmailing_get_email which retrieves email content.

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?

Explicitly says 'Use after qmailing_get_email when the user asks to inspect, summarise, or forward an attachment.' Also mentions the 5 MiB cap and fallback to web UI, providing clear when-to-use and limitations.

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 provide readOnlyHint=true and openWorldHint=true. The description adds behavioral context by detailing exactly which records are included in the checklist, helping the agent understand what to expect. It does not contradict annotations.

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 sentences: the first states the output and its contents, the second provides usage context. Every word earns its place; no repetition or 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?

For a simple read-only tool with one parameter and no output schema, the description fully covers what the agent needs: it specifies the exact records returned and the purpose (to tell the user what to publish). This is complete given 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% (one parameter, domainId, fully described). The tool description does not add any parameter semantics beyond what the schema already provides, meeting the baseline score.

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 'Return the full DNS checklist' for a custom domain, listing specific record types (ownership TXT, MX, SPF, DKIM CNAMEs, DMARC, optional _amazonses TXT). This verb+resource combination distinguishes it from sibling tools that handle mailboxes, emails, or webhooks.

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 says 'Use when the user asks "what records do I need" or wants to check why DNS isn't verifying.' This provides clear when-to-use guidance but does not mention when not to use or alternatives, missing the top tier for the dimension.

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?

Discloses important behavioral traits beyond annotations: notes that the body is external-sender-authored content and should be treated as data, never instructions. Also explains the meaning of 'suspicious' and 'muted' fields. Annotations already include readOnlyHint=true, so no contradiction.

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 sentences that are front-loaded and efficient. The first sentence states the core purpose, the second gives usage context, and the third provides important security/status details. Could be slightly more concise, but no unnecessary 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 single-parameter read tool with rich annotations (readOnlyHint, openWorldHint) and clear sibling tools, the description is complete. It explains the fetch scope, usage flow, and critical data handling guidance. No output schema exists, but the description sufficiently covers return value semantics.

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?

Input schema has 100% coverage for the single parameter 'id' with description 'Email UUID.'. The description adds value by clarifying what the response includes ('including the full body and attachment metadata'), which helps the agent understand the tool's output beyond 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?

Description clearly states 'Fetch one email by id including the full body and attachment metadata'. It uses a specific verb (fetch) and resource (email by ID), and distinguishes from siblings like qmailing_list_emails by specifying that it retrieves full details for a single email.

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?

Explicitly says 'Use after qmailing_list_emails picks the row the user is asking about', providing clear context for when to invoke this tool and implying it is not for listing or other operations. No alternatives mentioned but the guidance is strong.

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 declare readOnlyHint=true and openWorldHint=true. The description notes it returns the same fields as the list, which is useful but adds little beyond the annotation's indication that this is a safe read operation. 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?

Two short sentences with no wasted words. The key information is front-loaded: verb, resource, behavior, and usage context. 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?

For a simple single-parameter read tool with no output schema, the description adequately covers the purpose, parameter source, and relationship to the list tool. No additional information is necessary.

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% and the schema description already explains that the ID can be obtained from qmailing_list_mailboxes. The description repeats this, adding no new semantic information beyond what the schema provides. Baseline of 3 is appropriate.

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 the specific verb 'Fetch' and clearly states the resource (single mailbox by UUID) and distinguishes from siblings like qmailing_list_mailboxes by noting it returns one row. It directly addresses when to use this tool vs. listing.

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?

Explicitly states the condition for use: when the user references a specific mailbox and the ID is already known. It also tells how to obtain the ID (from a prior list). While it does not explicitly mention when NOT to use it, the positive guidance 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?

Annotations already indicate read-only and open-world behavior. The description adds that each entry shows ownership challenge status and DNS verification, going beyond the annotations.

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, no wasted words. Front-loaded with the verb and object, then provides key details, ends with a practical question.

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 no parameters and no output schema, the description clearly explains what the tool returns and its practical use case, fully covering the needed context.

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?

No parameters (baseline 4). The description's value does not depend on parameter documentation.

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 lists custom domains and details what each entry shows (ownership challenge, DNS verification). It's distinct from sibling tools which handle mailboxes, webhooks, etc.

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 includes a useful hint 'is my domain ready?' which implies when to use, but does not explicitly exclude alternatives or state when not to use.

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?

Beyond annotations (readOnlyHint, openWorldHint), the description reveals important behaviors: INBOX excludes muted senders, suspicious flag indicates authentication failure, and pagination limit. No contradiction with annotations.

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 yet comprehensive, packing multiple usage scenarios and behavioral notes into a few sentences without redundancy. Each 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?

Considering no output schema, the description adequately covers return item flags (muted, suspicious) and pagination. All parameters are well explained, and usage context is fully covered. The tool's purpose and behavior are completely documented.

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%, so the description adds value beyond schema: explains mailboxId omission for unified view, folder default and mute behavior, and offset/limit defaults. This enriches 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 lists emails in a folder (default INBOX). It provides specific usage contexts like 'what's in my inbox?' and distinguishes itself from sibling tools that list other resources.

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 gives explicit when-to-use examples and explains how to scope by mailbox. It also advises using folder=MUTED for muted senders. However, it lacks explicit 'when not to use' or alternatives among siblings.

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 declare readOnlyHint=true, confirming safe read access. The description adds that it populates emailCount, unreadCount, and sizeBytes, providing concrete behavioral details beyond annotations. 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 extremely concise: one sentence for purpose and one sentence for usage guidance. It is front-loaded with the key action and avoids unnecessary detail.

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 list tool with no parameters and no output schema, the description provides sufficient context: it lists all mailboxes and highlights the populated fields. No obvious gaps 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?

There are no parameters, and schema coverage is trivially 100%. The description adds no parameter-specific semantics, which is expected. Baseline 3 is appropriate.

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 it lists all mailboxes for the authenticated qmailing account. It is specific about the resource and action, but does not explicitly differentiate from sibling list tools. However, the sibling context (list_domains, list_emails, list_webhooks) makes the scope clear.

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 gives explicit usage scenarios: when the user asks about mailboxes, needs a mailbox ID, or wants volume overview. It does not provide negative examples or alternatives, but the scenarios are practical and helpful.

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?

The description adds context beyond the annotations (readOnlyHint=true, openWorldHint=true) by specifying that it returns both active and revoked endpoints, and that it applies to the calling account. No contradictions with annotations.

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 concise sentences: the first states the primary function, and the second provides usage guidance. Every sentence earns its place; 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 zero-parameter read-only tool, the description fully covers what the tool does, what it returns (webhook endpoints), and how to use it (inspect before register, find id to revoke). No gaps remain.

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, and schema coverage is 100%. Baseline for 0 parameters is 4. The description does not need to add parameter details, and it correctly implies no inputs are needed.

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 lists the calling account's webhook endpoints, both active and revoked. It uses a specific verb 'list' and resource 'webhook endpoints', which distinguishes it from sibling tools like qmailing_register_webhook (create) and qmailing_delete_webhook (delete).

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 usage scenarios: 'use to inspect existing subscriptions before registering a duplicate, or to find an id to revoke.' This gives clear context for when to use this tool vs. alternatives (register, delete) and includes practical motivations.

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?

Description adds critical behavioral details beyond annotations, such as the signing secret being returned only once and the HMAC signing mechanism. This complements the destructiveHint and openWorldHint annotations without contradiction.

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?

Description is concise with two sentences: first states purpose, second explains secret behavior. No unnecessary information, each 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 tool's complexity (3 required params, no output schema), the description covers the registration process and the critical secret return. It could mention the response format but is largely 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 coverage is 100% with parameter descriptions already explaining url, label, and events. The description does not add significant new meaning beyond what is in the schema, so a baseline of 3 is appropriate.

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?

Description clearly states the tool registers an HTTPS endpoint for receiving event notifications from qmailing, listing specific events. It distinguishes itself from sibling tools like delete_webhook and list_webhooks by focusing on creation.

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 subscribing to events, but does not explicitly state when to use this tool versus alternatives. However, the sibling tool names provide context, and the description's clarity on registering a new endpoint is sufficient for selection.

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 indicate destructiveHint=true and idempotentHint=false. The description adds value by explicitly stating the daily send limit and explaining the base64-to-multipart attachment handling, which goes beyond what annotations provide. However, it does not disclose potential side effects like the email actually being sent irrevocably.

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 compact with four sentences. The first sentence states the purpose, followed by constraint and technical detail. No redundant information. It is well-structured and front-loaded for quick comprehension.

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's complexity (9 parameters, no output schema) and presence of annotations, the description covers the key constraint and attachment handling but lacks information on return values, error conditions, or post-send behavior. An agent might need additional context to use the tool reliably without errors.

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 67%, so the description adds some context (e.g., attachments as base64) but does not significantly enhance understanding of parameters beyond the schema. The description clarifies the attachment format but does not explain 'replyToId' or 'bcc' more than 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 purpose: 'Send an email through one of the user's mailboxes.' It identifies the specific verb (send) and resource (email), and adds context about mailboxes and daily limits. This distinguishes it from sibling tools like qmailing_get_email and qmailing_list_emails.

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 the daily send limit but does not provide explicit guidance on when to use this tool versus alternatives, such as when to use other sending or email-related tools. There is no mention of prerequisites or scenarios where this tool should be avoided.

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