Dechonet MCP

ASN / BGP Lookup

asn_lookup

Read-onlyIdempotent

Look up ASN/BGP details for an IP address or AS number to identify the network operator, announced prefixes, abuse contact, and whether the IP is cloud/CDN-hosted.

Instructions

Look up Autonomous System (ASN) / BGP information for an IP address or AS number: the network operator, announced prefixes, abuse contact, and a classification (cloud, CDN, ISP, hosting, or enterprise). For an IPv4 address it also reports whether the address is on the Tor Project exit list, as information that does not change the result. Use this to identify who runs a network or whether an IP is cloud/CDN-hosted. Use reverse_dns instead for the host-level PTR name of a single IP. Read-only; requires no API key; rate-limited. Returns operator, prefixes, classification, and abuse contact.

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": {
      "query": "<query>"
    },
    "name": "asn_lookup"
  }
}

Input Schema

Name	Required	Description	Default
`query`	Yes	An IP address (e.g., '1.1.1.1') or an AS number in 'AS####' form (e.g., 'AS13335').

Output 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
`receipts`	No	Signed observation receipts behind this result, one per lookup: when, from where and under which rules version DechoNet observed it. Each url shows the record and checks its Ed25519 signature.
`reportUrl`	Yes	Human-facing interactive report for this exact lookup on dechonet.com
`observation`	No	How much was actually observed and when. A partial observation means some checks did not answer: missing parts are not verified, never clean.

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.5.14Oct 15, 2026

addedOutput schema / properties / observation

Added value: +{
+  "additionalProperties": false,
+  "description": "How much was actually observed and when. A partial observation means some checks did not answer: missing parts are not verified, never clean.",
+  "properties": {
+    "ageMinutes": {
+      "type": [
+        "number",
+        "null"
+      ]
+    },
+    "cached": {
+      "type": "boolean"
+    },
+    "observedAt": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "state": {
+      "enum": [
+        "complete",
+        "partial",
+        "unknown"
+      ],
+      "type": "string"
+    }
+  },
+  "required": [
+    "state",
+    "observedAt",
+    "cached",
+    "ageMinutes"
+  ],
+  "type": "object"
+}

addedOutput schema / properties / receipts

Added value: +{
+  "description": "Signed observation receipts behind this result, one per lookup: when, from where and under which rules version DechoNet observed it. Each url shows the record and checks its Ed25519 signature.",
+  "items": {
+    "additionalProperties": false,
+    "properties": {
+      "id": {
+        "type": "string"
+      },
+      "tool": {
+        "type": "string"
+      },
+      "url": {
+        "type": "string"
+      }
+    },
+    "required": [
+      "tool",
+      "id",
+      "url"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

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 / query / description

Previous value: -"ASN (e.g., AS13335) or IP address"New value: +"An IP address (e.g., '1.1.1.1') or an AS number in 'AS####' form (e.g., 'AS13335')."

First observedv0.1.0Jun 17, 2026

TDQS

A4.1/5.0

Behavior4/5

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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, and the description adds genuinely new operational context: no API key required, rate-limited, and a note that the Tor exit-list flag is informational only and does not alter the result. That last clarification is valuable because it prevents an agent from treating the lookup as a blocklist verdict. What is missing is any statement on invalid-input behavior or errors.

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 purpose and use case, and compact overall. The closing sentence ('Returns operator, prefixes, classification, and abuse contact') largely repeats the field list already given in the opening sentence, which is one redundant clause in an otherwise tight definition.

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

Completeness4/5

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

For a single-parameter read-only lookup with an output schema, this covers purpose, scope, safety profile, and rate-limit context adequately. The redundant return-field enumeration is unnecessary given the output schema, and error cases for malformed queries are unaddressed.

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 description coverage is 100% and the single `query` parameter already documents both accepted forms with examples. The description restates the same distinction ('for an IP address or AS number') without adding format or normalization detail, so it does not meaningfully extend 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?

Names a specific verb and resource ('Look up Autonomous System (ASN) / BGP information for an IP address or AS number') and enumerates the exact outputs (operator, prefixes, abuse contact, classification). It explicitly carves out the Tor-exit flag as IPv4-only, so an agent can distinguish it from reverse_dns and other lookup siblings.

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?

Gives a clear when-to-use statement ('identify who runs a network or whether an IP is cloud/CDN-hosted') and names one alternative with its selecting condition ('Use reverse_dns instead for the host-level PTR name'). It stops short of distinguishing from other overlapping siblings such as whois_lookup or ip_info, which an agent could plausibly reach for instead.

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