Uptimeify

asn_lookup

Read-only

Resolve a public IP address, or a domain, to the autonomous system that announces it: AS number and name, the announced prefix, country code, registry and allocation date. Answers who operates the network an address sits on, which tells a hosting provider from a CDN from a corporate network. It does not identify the site owner, and private or reserved addresses have no announcing AS. ip_geolocation returns the same AS data plus country and PTR. Anonymous and rate-limited per IP.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`query`	Yes	Public IP address or domain name

Output Schema

TableJSON Schema

Name	Required	Description	Default
`cc`	No
`ip`	No
`ok`	No
`asns`	No
`found`	No
`query`	No
`prefix`	No
`registry`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed15 schema fields changedSep 11, 2026

changedOutput schema / properties / asns / anyOf

Previous value: -[
-  {
-    "items": {
-      "additionalProperties": {},
-      "properties": {
-        "allocated": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "asn": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "cc": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "name": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        },
-        "registry": {
-          "anyOf": [
-            {
-              "type": "string"
-            },
-            {
-              "type": "null"
-            }
-          ]
-        }
-      },
-      "type": "object"
-    },
-    "type": "array"
-  },
-  {
-    "type": "null"
-  }
-]New value: +[
+  {
+    "items": {
+      "additionalProperties": {},
+      "properties": {
+        "allocated": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "asn": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "cc": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "name": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "registry": {
+          "type": [
+            "string",
+            "null"
+          ]
+        }
+      },
+      "type": "object"
+    },
+    "type": "array"
+  },
+  {
+    "type": "null"
+  }
+]

removedOutput schema / properties / cc / anyOf

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

addedOutput schema / properties / cc / 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 / ip / anyOf

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

addedOutput schema / properties / ip / type

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

removedOutput schema / properties / ok / anyOf

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

addedOutput schema / properties / ok / type

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

removedOutput schema / properties / prefix / anyOf

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

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

removedOutput schema / properties / query / anyOf

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

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

removedOutput schema / properties / registry / anyOf

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

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

Changed1 schema field changedAug 4, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": {},
+  "properties": {
+    "asns": {
+      "anyOf": [
+        {
+          "items": {
+            "additionalProperties": {},
+            "properties": {
+              "allocated": {
+                "anyOf": [
+                  {
+                    "type": "string"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ]
+              },
+              "asn": {
+                "anyOf": [
+                  {
+                    "type": "string"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ]
+              },
+              "cc": {
+                "anyOf": [
+                  {
+                    "type": "string"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ]
+              },
+              "name": {
+                "anyOf": [
+                  {
+                    "type": "string"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ]
+              },
+              "registry": {
+                "anyOf": [
+                  {
+                    "type": "string"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ]
+              }
+            },
+            "type": "object"
+          },
+          "type": "array"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "cc": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "found": {
+      "anyOf": [
+        {
+          "type": "boolean"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "ip": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "ok": {
+      "anyOf": [
+        {
+          "type": "boolean"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "prefix": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "query": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "registry": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    }
+  },
+  "type": "object"
+}

First observedAug 4, 2026

TDQS

A4.4/5.0

Behavior5/5

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

Annotations only declare readOnlyHint, so the description carries real weight here and delivers: 'Anonymous and rate-limited per IP' discloses the absence of auth plus a throttling constraint, and 'private or reserved addresses have no announcing AS' pre-empts a whole class of empty results. It also enumerates the returned fields, which goes beyond the safety profile.

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

Conciseness4/5

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

Front-loaded with the verb and resource, then constraints, then the sibling comparison, then the operational caveat — a sensible ordering. Three sentences with almost no waste, though the 'which tells a hosting provider from a CDN' clause is interpretive framing rather than call-critical detail.

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 explained, and the description still covers the input contract, failure modes, rate limiting, and the adjacent tool. For a one-parameter, read-only lookup, nothing an agent needs in order to call it correctly 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?

Schema coverage is 100% for the single 'query' parameter, so the schema already defines it as a public IP or domain name, making 3 the baseline. The description adds only the boundary condition that private/reserved inputs yield nothing; it does not add format, IPv6, or CIDR guidance beyond the schema.

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?

Uses a specific verb ('Resolve') on a specific resource ('public IP address, or a domain') and names exactly what comes back: AS number and name, announced prefix, country code, registry, allocation date. It explicitly differentiates itself from the sibling ip_geolocation, so an agent can route without opening either schema.

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

Usage Guidelines4/5

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

It states the selecting condition against the alternative: 'ip_geolocation returns the same AS data plus country and PTR,' which tells the agent when the sibling is the better pick. It also frames the use case ('who operates the network... hosting provider from a CDN from a corporate network'). What's missing is an explicit rule such as 'prefer this when you only need AS data,' so usage is strongly implied rather than spelled out.

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?