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networking_ipv4_to_ipv6

Read-onlyIdempotent

Convert an IPv4 address to multiple IPv6 formats (mapped, compatible, 6to4) and classify it using offline arithmetic. No network lookup required.

Instructions

IPv4 to IPv6 Converter. Convert a single IPv4 address into its IPv6 representations using offline bit/string arithmetic, with no DNS or live network lookup. Returns the IPv4-mapped form (compressed, expanded, and dotted-suffix), the deprecated IPv4-compatible form (compressed and expanded), the 6to4 prefix (only for public addresses; null for private/loopback), plus the address packed as hexadecimal and dotted binary. Also classifies the input (A-E class, public/ private/loopback/link-local/multicast/reserved type). Use network_subnet_calculator or network_cidr_calculator instead for subnet planning and CIDR notation; this tool only transforms one host address to IPv6 notation and does not parse CIDR. Accepts one dotted-decimal IPv4 (e.g. 192.168.1.1), no CIDR suffix. Read-only, non-destructive, contacts no external service, and rate-limited (60 req/min, 500/hr anonymous).

Input Schema

TableJSON Schema

Name	Required	Description	Default
`ipv4`	Yes	The IPv4 address to convert, in dotted-decimal notation with four octets 0-255 and no CIDR suffix.
`input`	No	Deprecated alias for ipv4, used only when ipv4 is omitted; same dotted-decimal format.

Output Schema

TableJSON Schema

Name	Required	Description
`success`	No	True when the address was valid and converted; false on invalid input.
`error`	No	Error message present only when success is false (e.g. invalid IPv4 address format).
`result`	No	Conversion output, present only when success is true.

Schema Changelog

Changes observed during successful MCP inspections.

Changed6 schema fields changedv0.5.1Jun 3, 2026

addedInput schema / additionalProperties
```
Added value: +false
```

addedInput schema / properties / input

Added value: +{
+  "description": "Deprecated alias for ipv4, used only when ipv4 is omitted; same dotted-decimal format.",
+  "format": "ipv4",
+  "type": "string"
+}

addedInput schema / properties / ipv4 / description

Added value: +"The IPv4 address to convert, in dotted-decimal notation with four octets 0-255 and no CIDR suffix."

addedInput schema / properties / ipv4 / examples
```
Added value: +[
+  "8.8.8.8"
+]
```
addedInput schema / properties / ipv4 / format
```
Added value: +"ipv4"
```

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "error": {
+      "description": "Error message present only when success is false (e.g. invalid IPv4 address format).",
+      "type": "string"
+    },
+    "result": {
+      "description": "Conversion output, present only when success is true.",
+      "properties": {
+        "binary": {
+          "description": "The four octets as dot-separated 8-bit binary strings.",
+          "type": "string"
+        },
+        "hexadecimal": {
+          "description": "The four octets packed as eight contiguous hex digits.",
+          "type": "string"
+        },
+        "info": {
+          "description": "Classification of the input IPv4 address.",
+          "properties": {
+            "addressClass": {
+              "description": "Classful network letter (A, B, C, D (Multicast), or E (Reserved)).",
+              "type": "string"
+            },
+            "description": {
+              "description": "Human-readable description of the address type.",
+              "type": "string"
+            },
+            "isLoopback": {
+              "description": "True if the address is in 127.0.0.0/8.",
+              "type": "boolean"
+            },
+            "isPrivate": {
+              "description": "True if the address is in an RFC 1918 private range.",
+              "type": "boolean"
+            },
+            "type": {
+              "description": "Address type such as Public, Private (RFC 1918), Loopback, Link-Local (APIPA), Multicast, or Reserved.",
+              "type": "string"
+            }
+          },
+          "type": "object"
+        },
+        "ipv4Compatible": {
+          "description": "Compressed deprecated IPv4-compatible IPv6 address.",
+          "type": "string"
+        },
+        "ipv4CompatibleExpanded": {
+          "description": "Fully expanded IPv4-compatible address with all eight zero-padded hextets.",
+          "type": "string"
+        },
+        "ipv4Mapped": {
+          "description": "Compressed IPv4-mapped IPv6 address, e.g. ::ffff:0808:0808.",
+          "type": "string"
+        },
+        "ipv4MappedDotted": {
+          "description": "IPv4-mapped address keeping the original dotted-decimal suffix, e.g. ::ffff:8.8.8.8.",
+          "type": "string"
+        },
+        "ipv4MappedExpanded": {
+          "description": "Fully expanded IPv4-mapped address with all eight zero-padded hextets.",
+          "type": "string"
+        },
+        "originalIPv4": {
+          "description": "The trimmed IPv4 address that was converted.",
+          "type": "string"
+        },
+        "sixToFour": {
+          "description": "6to4 prefix (2002:hhhh:hhhh::/48) for public addresses; null for private or loopback input.",
+          "type": [
+            "string",
+            "null"
+          ]
+        }
+      },
+      "type": "object"
+    },
+    "success": {
+      "description": "True when the address was valid and converted; false on invalid input.",
+      "type": "boolean"
+    }
+  },
+  "type": "object"
+}

First observedv0.1.0May 31, 2026

TDQS

A4.9/5.0

Behavior5/5

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

Description adds behavioral details beyond annotations: read-only, non-destructive, no external service contacts, rate limits (60 req/min, 500/hr). Also enumerates output types and classification. No contradictions with annotations.

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?

Single well-structured paragraph with each sentence adding value: purpose, method, output types, sibling differentiation, input format, behavioral notes. No wasted words.

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?

Given output schema exists, description does not need to detail return values but still lists them. Covers all necessary context for a two-parameter tool with high schema coverage.

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?

Schema coverage is 100% with descriptions. Description adds that ipv4 must be dotted-decimal without CIDR suffix, and that input is a deprecated alias. This adds context beyond 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?

Description starts with 'IPv4 to IPv6 Converter' and clearly states it converts a single IPv4 address to IPv6 representations using offline arithmetic, distinguishing it from sibling tools for subnet planning and CIDR notation.

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 instructs to use network_subnet_calculator or network_cidr_calculator for subnet planning, and clarifies this tool only transforms one host address without CIDR parsing. States input format explicitly.

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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