Calculate IPv4 CIDR subnet mask, wildcard, network, broadcast, usable IPs, and host count from a CIDR block.
Calculate IPv4 CIDR subnet mask, wildcard mask, network address, broadcast address, usable IP range, and total host count.
| Name | Required | Description | Default |
|---|---|---|---|
| cidr | Yes | IPv4 CIDR block such as '192.168.1.0/24', '10.0.0.0/16', or '/24' |
Changes observed during successful MCP inspections.
v1.3.4Input schema / additionalPropertiesAdded value: +falseInput schema / properties / cidr / descriptionPrevious value: -"CIDR string like 192.168.1.0/24 or /24"New value: +"IPv4 CIDR block such as '192.168.1.0/24', '10.0.0.0/16', or '/24'"v1.3.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered structurally. The description adds nothing further behaviorally — no mention of how malformed CIDRs are handled or whether host bits set in the address are accepted — so it neither helps nor hurts beyond the annotations.
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 sentence, zero filler, output list front-loaded immediately after the verb. Nothing padded and nothing left dangling.
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, the description usefully enumerates the six returned values so the agent knows what it gets back, and the annotations cover the safety profile. It falls short only on edge-case behavior (invalid or malformed CIDR input), which an agent might need to plan around.
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 description coverage is 100% and the single parameter's schema text already gives three concrete formats including the shorthand '/24'. The description adds no syntax or constraint detail beyond what the schema provides, so the baseline 3 applies.
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?
States a specific verb ('Calculate') and resource ('IPv4 CIDR') and enumerates exactly what is produced: subnet mask, wildcard mask, network address, broadcast address, usable range, host count. None of the unrelated siblings (castov_hash, castov_jwt_decode, castov_cron, etc.) can be confused with it.
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?
Usage is implied by the name and the output list — an agent will reach for this when it needs subnet math — but there is no explicit statement of when to use it versus anything else, no preconditions, and no note on invalid input. For a single-purpose utility with no competing sibling, implied usage is adequate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.