net-mcp

Subnet Info

subnet_info

Retrieve network details for any IP prefix or address, including network/broadcast addresses, netmask, host count, and address classification. Supports both IPv4 and IPv6.

Instructions

Get detailed information about an IP prefix or address.

Returns network/broadcast addresses, netmask, host count, and classification (private, global, multicast, etc.). Works with both IPv4 and IPv6.

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": {
      "prefix": "<prefix>"
    },
    "name": "subnet_info"
  }
}

Input Schema

Name	Required	Description	Default
`prefix`	Yes	IP prefix in CIDR (e.g. '10.0.0.0/24') or single IP (e.g. '1.1.1.1')

Output Schema

Name	Required	Description
`prefix`	Yes
`netmask`	Yes
`hostmask`	Yes
`is_global`	Yes
`ip_version`	Yes
`is_private`	Yes
`is_loopback`	Yes
`is_multicast`	Yes
`usable_hosts`	Yes	Usable hosts; a decimal string when it exceeds 2^53 (large IPv6 ranges)
`is_link_local`	Yes
`prefix_length`	Yes
`network_address`	Yes
`total_addresses`	Yes	Total addresses; a decimal string when it exceeds 2^53 (large IPv6 ranges)
`broadcast_address`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 22, 2026

TDQS

A3.8/5.0

Behavior4/5

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

With no annotations, the description carries the behavioral disclosure burden. It clearly states what is returned (network/broadcast addresses, netmask, host count, classification) and that it works with both IPv4 and IPv6, giving concrete expectations. It does not mention invalid input behavior, but for a read-only info tool this is a reasonable level of transparency.

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 three compact sentences with no filler. It front-loads the core purpose and then lists outputs and compatibility in an easily scannable way.

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 one-parameter lookup tool with an output schema, the description covers purpose, return content, and protocol scope. It lacks explicit sibling differentiation and edge-case behavior, but the tool is simple enough that the description is substantially complete.

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 schema already documents the prefix parameter with format examples. The description adds useful context about IPv4/IPv6 support but does not add substantial new meaning beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Get') and names the resource ('detailed information about an IP prefix or address'), and it enumerates the key outputs. It does not explicitly distinguish it from sibling tools like subnet_split or ip_contains, but its purpose is unambiguous.

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

Usage Guidelines3/5

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

Usage is implied: an agent would use this tool when it needs detailed information about an IP prefix or address. However, there is no explicit guidance about when not to use it or which sibling tools to prefer for related operations such as splitting subnets or checking containment.

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