listDomainsList all inbound domains for the organization, both verified and unverified. Each domain includes its verification status and DNS records. Use before addDomain to check whether a domain is already claimed.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes | ||
| tool | Yes | ||
| status | Yes | ||
| statusText | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint: true, idempotentHint: true, and destructiveHint: false. The description adds that the tool returns verification status and DNS records, which is useful context without contradicting 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 concise sentences with no wasted words. It front-loads the action and scope, followed by a practical usage hint.
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 zero parameters and an output schema present, the description fully covers the tool's behavior: listing all inbound domains with verification status and DNS records, and provides a use-case (before addDomain).
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 the description adds meaning beyond the schema by explaining the output content (verification status, DNS records) and the tool's purpose, which is fully adequate given the parameter count is zero.
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 'list', the resource 'inbound domains', and the scope 'both verified and unverified'. It also mentions the output includes verification status and DNS records, distinguishing it from related tools like addDomain.
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 advises 'Use before addDomain to check whether a domain is already claimed', providing a clear when-to-use scenario and indicating an alternative tool.
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 resource or action: domain management (addDomain, verifyDomain), sending (sendEmail, replyToEmail), receiving (getEmail, listEmails), webhooks (createEndpoint, listWebhookDeliveries), status (getAccount, getInboxStatus), etc. There is no overlap in purpose, and descriptions clearly differentiate them.
All tools follow a consistent verb_noun pattern in snake_case, such as listDomains, createFilter, downloadEmailAttachments, and getSentEmail. The verbs (get, list, create, delete, send, reply, etc.) are used predictably, with no mixing of conventions.
29 tools is slightly on the high side but still reasonable for an email server covering domains, sending, receiving, webhooks, filters, and status. Each tool serves a specific purpose and earns its place, though some consolidation might be possible.
The tool set covers core email workflows: domain setup (add, verify, list), sending/receiving, threading, webhook lifecycle, and filtering. Minor gaps exist, such as missing deleteDomain or updateEndpoint, but the surface is largely complete for the intended domain.