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DemiSignal

by demisignal.com · remote · no sign-in to list tools · v1.0.0 · published by com.demisignal

Check a domain's DMARC, SPF, DKIM, MX, BIMI and MTA-STS records. Generate SPF and DMARC records.

Changes · 3
CompareRegistry entry

3 tools: 3 change things.

Scanned Oct 21, 2026

2 checks matched something in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http demisignal https://demisignal.com/mcp?utm_source=mcp-registry

Findings

Matches of fixed checks, with the text they matched.

2 warn
  • Warngenerate_spf_record

    The server marks "generate_spf_record" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

    Matched text

    annotations: {"readOnlyHint":true,"idempotentHint":true}; The name "generate_spf_record" says "generate": a word for a change.

    What this check looks for
  • Warngenerate_dmarc_record

    The server marks "generate_dmarc_record" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

    Matched text

    annotations: {"readOnlyHint":true,"idempotentHint":true}; The name "generate_dmarc_record" says "generate": a word for a change.

    What this check looks for

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

3 tools

Changes things 3Claude Code: ask
  • check_domainLook up a domain's live DNS and grade its email authentication: DMARC, SPF, DKIM (common selectors), MX, BIMI and MTA-STS.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Look up a domain's live DNS and grade its email authentication: DMARC, SPF, DKIM (common selectors), MX, BIMI and MTA-STS. Returns each record, its status and the issues found, with a guide link per issue. A domain checked in the last few minutes is answered from that check.

    Annotations the server declares

    • title: Check a domain's email authentication
    • readOnlyHint: true
    • openWorldHint: true
    • idempotentHint: true
  • generate_dmarc_recordBuild a DMARC TXT record and the host to publish it at, from a policy and the addresses that should receive aggregate reports.1 finding

    Why it is in this group

    • The name "generate_dmarc_record" says "generate": a word for a change.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "generate_dmarc_record" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

      Matched text

      annotations: {"readOnlyHint":true,"idempotentHint":true}; The name "generate_dmarc_record" says "generate": a word for a change.

      What this check looks for
    Description, as the server wrote it
    Build a DMARC TXT record and the host to publish it at, from a policy and the addresses that should receive aggregate reports. Notes what the record does not cover yet. Computes from the arguments only; nothing is looked up or stored.

    Annotations the server declares

    • title: Generate a DMARC record
    • readOnlyHint: true
    • idempotentHint: true
  • generate_spf_recordBuild an SPF TXT record from the services and servers that send email for a domain, with an estimate of the DNS lookups it uses against SPF's limit of 10.1 finding

    Why it is in this group

    • The name "generate_spf_record" says "generate": a word for a change.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "generate_spf_record" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

      Matched text

      annotations: {"readOnlyHint":true,"idempotentHint":true}; The name "generate_spf_record" says "generate": a word for a change.

      What this check looks for
    Description, as the server wrote it
    Build an SPF TXT record from the services and servers that send email for a domain, with an estimate of the DNS lookups it uses against SPF's limit of 10. Computes from the arguments only; nothing is looked up or stored.

    Annotations the server declares

    • title: Generate an SPF record
    • readOnlyHint: true
    • idempotentHint: true

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http demisignal https://demisignal.com/mcp?utm_source=mcp-registry

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [],
    "ask": [
      "mcp__demisignal__check_domain",
      "mcp__demisignal__generate_spf_record",
      "mcp__demisignal__generate_dmarc_record"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as demisignal. Review it before you use it.