Calculate subnet facts for any CIDR address, including network, mask, wildcard, broadcast, host range, host count, and class to plan or troubleshoot IP addressing.
Subnet facts for an address/prefix: network, mask, wildcard, broadcast, host range, count, class.
| Name | Required | Description | Default |
|---|---|---|---|
| cidr | Yes |
Changes observed during successful MCP inspections.
v0.1.6Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered and the bar is lower. The description adds that this is a pure derivation over an address/prefix, but says nothing about behavior on malformed or host-bit-set input (error vs. normalization) or output format, which matters for a calculator-like tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
One front-loaded sentence with the resource stated first and the returned fields enumerated compactly — no filler. It reads as a fragment, but every element earns its place and nothing is buried.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With no output schema, listing the returned fields is exactly the right compensatory move and covers most of what an agent needs to know about the result. The remaining gap is input expectations (CIDR syntax/validation) rather than output, which the 0% schema coverage leaves unaddressed.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 0% for the single `cidr` parameter, so the description must carry the load. The phrase 'address/prefix' usefully implies the expected form (e.g. 192.168.0.0/24) and that a prefix length is bundled in, which is real added meaning, but it gives no example, no accepted range, and no note on whether a bare address with a separate mask is allowed.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the resource — subnet facts derived from an address/prefix — and enumerates exactly which facts (network, mask, wildcard, broadcast, host range, count, class). It does not name or contrast with sibling calculators like net_vlsm, net_summarize, or net_split, so an agent must infer that this is the per-subnet detail tool rather than the sizing/summarizing one.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
There is no when-to-use or when-not-to-use guidance and no mention of the sibling tools in the same family. The agent gets no signal about choosing net_subnet over net_vlsm/net_split when handed a CIDR, nor any prerequisite such as valid CIDR formatting.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.