ip_in_subnet

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

With no annotations, the description carries full behavioral burden. It does disclose output behavior by mentioning the range display and protocol scope, but it does not cover edge cases like invalid IP/CIDR input, exact return format, or whether the operation is purely read-only.

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?

The description is a single, tightly-packed sentence: primary action first, secondary output second, and protocol coverage last. There is no filler or redundancy, and every clause contributes meaningful information.

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?

For a simple two-parameter tool with fully documented schema, this description covers the core behavior and output sufficiently. It lacks only edge-case handling and precise return structure details, which is a minor gap given there is no output schema and the operation is straightforward.

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 100%, so the schema already documents both params. The description adds no extra parameter-level detail beyond what is already present, such as format requirements or examples, so the baseline score of 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?

The description clearly states the specific operation: checking whether an IP address is inside a CIDR block. It also names the secondary output (first-to-last range) and declares IPv4/IPv6 support, which distinguishes it from sibling tools like subnet_calc and ip_convert that serve different purposes.

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?

The usage context is implied by the description: use it when a membership test is needed. However, it gives no explicit guidance about when not to use it or how it compares to sibling alternatives such as subnet_calc, ip_convert, or ipv6_normalize.

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