Domain DNS info

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

The description adds behavioral context beyond the readOnlyHint annotation by clarifying that data is what 'Shodan has seen,' implying historical/passive DNS data rather than a live query. It does not discuss potential limitations like data staleness or completeness, but the annotation already indicates a non-mutating operation, and the description adds meaningful context above that.

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 two sentences and front-loaded with the core function. The first sentence states the purpose, the second adds usage guidance. There is no redundant information or filler.

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?

The tool is simple with one parameter, and the description conveys the primary output (subdomains and DNS entries) and a clear use case. There is no output schema, but the description provides enough high-level context for an agent to understand what to expect. It could mention output format or that results are based on Shodan's historical database, but the current level is adequate for typical use.

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?

The input schema fully describes the single 'domain' parameter with a clear example. The description does not add additional parameter-level semantics beyond restating 'for a domain,' so it provides no extra value over the schema's 100% coverage. The baseline 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 states a specific verb ('Look up') and resource ('subdomains and DNS entries Shodan has seen for a domain'), clearly distinguishing it from sibling tools like shodan_dns_resolve and shodan_dns_reverse. It is immediately obvious what the tool does.

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 description provides a clear use case: 'Use this to map out your own domain's exposed surface.' This gives context for when to use the tool, though it does not explicitly mention alternatives or when not to use it. That is sufficient for a simple tool.

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