Uptimeify

MX lookup

mx_lookup

Read-only

Looks up a domain's MX records and resolves each mail exchanger to its IPv4 and IPv6 addresses, ordered by priority, flagging hosts that resolve into private address space. Shows where mail is delivered; it does not connect to the servers or test SMTP, and sender authorisation is covered by spf_check, dkim_check and dmarc_check. Anonymous, rate-limited per IP.

Input Schema

Name	Required	Description	Default
`domain`	Yes	Domain name, e.g. deinkunde.com

Output Schema

Name	Required	Description	Default
`ok`	No
`found`	No
`domain`	No
`servers`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed7 schema fields changedSep 11, 2026

removedOutput schema / properties / domain / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / domain / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / found / anyOf

Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / found / type
```
Added value: +[
+  "boolean",
+  "null"
+]
```

removedOutput schema / properties / ok / anyOf

Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / ok / type

Added value: +[
+  "boolean",
+  "null"
+]

changedOutput schema / properties / servers / anyOf

Previous value: -[
-  {
-    "items": {
-      "additionalProperties": {},
-      "properties": {
-        "exchange": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "ipv4": {
-          "anyOf": [
-            {
-              "items": {
-                "type": "string"
-              },
-              "type": "array"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "ipv6": {
-          "anyOf": [
-            {
-              "items": {
-                "type": "string"
-              },
-              "type": "array"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "priority": {
-          "anyOf": [
-            {
-              "type": "number"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "private": {
-          "anyOf": [
-            {
-              "type": "boolean"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        }
-      },
-      "type": "object"
-    },
-    "type": "array"
-  },
-  {
-    "type": "null"
-  }
-]New value: +[
+  {
+    "items": {
+      "additionalProperties": {},
+      "properties": {
+        "exchange": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "ipv4": {
+          "anyOf": [
+            {
+              "items": {
+                "type": "string"
+              },
+              "type": "array"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
+        "ipv6": {
+          "anyOf": [
+            {
+              "items": {
+                "type": "string"
+              },
+              "type": "array"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
+        "priority": {
+          "type": [
+            "number",
+            "null"
+          ]
+        },
+        "private": {
+          "type": [
+            "boolean",
+            "null"
+          ]
+        }
+      },
+      "type": "object"
+    },
+    "type": "array"
+  },
+  {
+    "type": "null"
+  }
+]

Changed1 schema field changedAug 4, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": {},
+  "properties": {
+    "domain": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "found": {
+      "anyOf": [
+        {
+          "type": "boolean"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "ok": {
+      "anyOf": [
+        {
+          "type": "boolean"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "servers": {
+      "anyOf": [
+        {
+          "items": {
+            "additionalProperties": {},
+            "properties": {
+              "exchange": {
+                "anyOf": [
+                  {
+                    "type": "string"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ]
+              },
+              "ipv4": {
+                "anyOf": [
+                  {
+                    "items": {
+                      "type": "string"
+                    },
+                    "type": "array"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ]
+              },
+              "ipv6": {
+                "anyOf": [
+                  {
+                    "items": {
+                      "type": "string"
+                    },
+                    "type": "array"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ]
+              },
+              "priority": {
+                "anyOf": [
+                  {
+                    "type": "number"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ]
+              },
+              "private": {
+                "anyOf": [
+                  {
+                    "type": "boolean"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ]
+              }
+            },
+            "type": "object"
+          },
+          "type": "array"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    }
+  },
+  "type": "object"
+}

First observedAug 4, 2026

TDQS

A4.7/5.0

Behavior5/5

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

Annotations only declare readOnlyHint and openWorldHint; the description adds real operational context: anonymous access, per-IP rate limiting, priority ordering of results, and flagging of hosts resolving into private address space. That is meaningful behavior beyond the structured hints.

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 front-loaded sentences: capability first, boundaries and routing second, access constraints last. No filler and nothing repeated from the title or schema.

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?

An output schema exists so return values need not be described, and the description covers scope, exclusions, access model and rate limits. Nothing an agent needs to select or call this tool is missing.

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

Parameters3/5

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

Only one parameter (domain) and schema coverage is 100% with an example already in the schema, so the description adds no syntax or format detail. Baseline 3 applies when the schema carries the parameter semantics.

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 and resource (looks up a domain's MX records) plus the resolution behavior (each exchanger to IPv4/IPv6, ordered by priority, private-space flagging). It is immediately distinguishable from siblings like check_dns or spf_check.

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?

Explicitly scopes when to use it ('shows where mail is delivered') and when not ('does not connect to the servers or test SMTP'), and routes sender-authorisation questions to the named alternatives spf_check, dkim_check and dmarc_check.

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

All Uptimeify 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?