Dechonet MCP

Email Authentication Check

email_auth

Read-onlyIdempotent

Evaluate a domain's email authentication and deliverability by checking MX, SPF, DMARC, DKIM, BIMI, MTA-STS, TLS-RPT, DANE, and blacklists, returning a 0-100 score with actionable fixes.

Instructions

Assess a domain's email authentication and deliverability posture: MX records, SPF, DMARC, DKIM (probes 15 common selectors), BIMI, MTA-STS, TLS-RPT, and DANE, plus a blacklist check across all MX hosts, returning a 0-100 deliverability score. Use this for a full sending/receiving readiness review of a domain. Use dns_lookup instead if you only need raw TXT/MX records, or email_header_analysis to diagnose a specific message that was already sent. Read-only; requires no API key; rate-limited. Returns a text report: score, per-mechanism KPIs, issues, and actions.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`domain`	Yes	Email domain to assess — the part after '@' (e.g., 'example.com'). An IP address is also accepted for reverse/PTR-based checks.

Output Schema

TableJSON Schema

Name	Required	Description
`kpis`	No	Key metrics as label/value pairs
`grade`	No	Letter grade (A+ to F) when the tool grades the target
`score`	No	0-100 score when the tool scores the target
`issues`	No	Detected problems, severity-rated
`status`	Yes	Overall verdict, e.g. 'good' \| 'warning' \| 'bad' \| 'info' \| 'unknown'
`actions`	No	Recommended next actions, most important first
`summary`	No	One-paragraph interpretation of the result
`reportUrl`	Yes	Human-facing interactive report for this exact lookup on dechonet.com

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv1.1.0Sep 8, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": false,
+  "properties": {
+    "actions": {
+      "description": "Recommended next actions, most important first",
+      "items": {
+        "type": "string"
+      },
+      "type": "array"
+    },
+    "grade": {
+      "description": "Letter grade (A+ to F) when the tool grades the target",
+      "type": "string"
+    },
+    "issues": {
+      "description": "Detected problems, severity-rated",
+      "items": {
+        "additionalProperties": false,
+        "properties": {
+          "key": {
+            "type": "string"
+          },
+          "severity": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "severity",
+          "key"
+        ],
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "kpis": {
+      "description": "Key metrics as label/value pairs",
+      "items": {
+        "additionalProperties": false,
+        "properties": {
+          "label": {
+            "type": "string"
+          },
+          "value": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "label",
+          "value"
+        ],
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "reportUrl": {
+      "description": "Human-facing interactive report for this exact lookup on dechonet.com",
+      "type": "string"
+    },
+    "score": {
+      "description": "0-100 score when the tool scores the target",
+      "type": "number"
+    },
+    "status": {
+      "description": "Overall verdict, e.g. 'good' | 'warning' | 'bad' | 'info' | 'unknown'",
+      "type": "string"
+    },
+    "summary": {
+      "description": "One-paragraph interpretation of the result",
+      "type": "string"
+    }
+  },
+  "required": [
+    "status",
+    "reportUrl"
+  ],
+  "type": "object"
+}

Changed1 schema field changedv1.0.3Jun 17, 2026

changedInput schema / properties / domain / description

Previous value: -"Domain or IP to check (e.g., example.com or 1.2.3.4)"New value: +"Email domain to assess — the part after '@' (e.g., 'example.com'). An IP address is also accepted for reverse/PTR-based checks."

First observedv0.1.0Jun 17, 2026

TDQS

A4.9/5.0

Behavior5/5

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

The description goes beyond the readOnlyHint and idempotentHint annotations by explaining that the tool performs DNS probes, blacklist checks, and returns a 0-100 score plus a text report. It also discloses the rate limit and the fact that no API key is required, giving an agent a clear picture of behavior and constraints.

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?

The description is well-organized: it first states what the tool does and what it returns, then gives the primary use case, then explicitly names alternative tools, and finally lists operational constraints. No sentences are wasted and the structure makes it easy for an agent to scan.

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 a tool with many checks (MX, SPF, DMARC, DKIM, BIMI, MTA-STS, TLS-RPT, DANE, blacklists), the description gives enough detail to set expectations without overwhelming. It specifies the output format (score, per-mechanism KPIs, issues, actions) and provides enough context for an agent to decide whether this tool is appropriate.

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?

The schema covers the single required domain parameter, and the description adds meaningful clarification: it defines the expected input as the part after '@', provides an example, and notes that an IP address is accepted for reverse/PTR checks. This is more helpful than the schema alone, though it does not cover edge cases like punycode or trailing dots.

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?

The description opens with the specific verb 'Assess' and identifies the exact resource: a domain's email authentication and deliverability posture. It clearly distinguishes this tool from dns_lookup and email_header_analysis by naming those alternatives and their narrower use cases.

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?

It explicitly states when to use the tool ('for a full sending/receiving readiness review of a domain') and when not to, directing users to dns_lookup for raw records and email_header_analysis for a specific message. It also provides operational constraints: read-only, no API key required, and rate-limited.

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

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