Mailercloud

Update Domain (preview, then confirm)

update_domain

DestructiveIdempotent

Change a sending domain's record host names (tracking_prefix, dkim_selector, dkim2_selector, image_prefix) and/or open tracking. Only the fields given change. A changed selector or prefix breaks the DNS records already published until the user publishes the new ones and runs verify_domain, so it shows a preview first and changes only with confirm: true.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "domain_id": "<domain_id>"
    },
    "name": "update_domain"
  }
}

Input Schema

Name	Required	Description
`confirm`	No	Must be true to make the change. Leave it out first to get a preview, show it to the user, and ask them to confirm
`dry_run`	No	Validate and show what would change without changing anything
`domain_id`	Yes	Domain ID (from list_domains)
`image_prefix`	No	New host label of the image record (letters, digits and dots, up to 25)
`dkim_selector`	No	New DKIM selector (letters and digits, up to 3)
`open_tracking`	No	Turn open tracking for Email API and SMTP mail on or off
`dkim2_selector`	No	New second DKIM selector (letters and digits, up to 3)
`tracking_prefix`	No	New host label of the tracking record (letters and digits, up to 25)

Schema Changelog

Changes observed during successful MCP inspections.

AddedNov 4, 2026

TDQS

A4.9/5.0

Behavior5/5

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

Annotations already declare destructiveHint=true and readOnlyHint=false, and the description supplies the missing why: a changed selector or prefix breaks already-published DNS records until new ones are published and verified. It also documents the partial-update rule ('only the fields given change') and the confirm gate, which is behavior no annotation conveys.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences, front-loaded with the change scope, then the partial-update rule, then the risk and confirm mechanism. Nothing is repeated from the schema and no sentence could be dropped without losing decision-relevant information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For an 8-parameter destructive mutation with full schema coverage and no output schema, the description covers everything an agent needs: what changes, what stays, why it is risky, and the required confirm workflow. The remaining unknown, the preview payload shape, is a minor gap given the explicit confirm gate.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so field meanings and formats (letter/digit constraints, lengths) are already documented; the description rightly avoids repeating them. It does add one genuinely useful semantic not in the schema: omitted fields are left untouched, making this a partial rather than full replacement update.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (change) and resource (a sending domain's record host names and open tracking) and enumerates the exact mutable fields, so the agent can distinguish it from siblings like add_domain, delete_domain, get_domain and verify_domain without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives an explicit two-step workflow: call without confirm to get a preview, show it to the user, then call with confirm: true to apply. It also names the follow-up dependency on verify_domain after changing a selector or prefix, which is the condition an agent would otherwise have to infer.

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

All Mailercloud tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources

Need Help?