dns_recon

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly states the tool is passive and uses only public data, which is a meaningful non-intrusive guarantee, and it documents a per-query timeout. It could additionally cover failure modes or rate-limit risks, but the core behavioral profile is clearly conveyed.

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 front-loaded with the purpose, then organized into Args and Returns sections without redundancy. The Returns detail is somewhat lengthy but justified because there is no output schema, and every line adds operational value.

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?

Given no output schema, the description supplies a structured return contract keyed by checks, including the nested DNS record types and email security signals. All three parameters are documented, the default behavior is explained, and the passive/public-data constraint is stated, making the tool fully callable by an agent.

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 0%, so the description must fully explain the parameters, and it does: domain gets an example, checks are enumerated with a default behavior, and timeout is defined as seconds. This fully compensates for the empty schema descriptions and adds meaning beyond the field names.

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 opens with a specific verb and resource: 'Passive DNS/WHOIS reconnaissance for a domain using only public data.' It clearly distinguishes this tool from active siblings like port_scan and tls_check by emphasizing passivity and public data, and the Args/Returns sections further define its exact scope.

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 'Passive... using only public data' phrasing provides clear context for when to choose this tool over active reconnaissance tools, and the checks list tells the agent what subsets of work it can request. It does not explicitly name alternatives or state when not to use it, so it falls just short of a 5.

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