Subdomain Discovery

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

With annotations already declaring readOnlyHint=true and idempotentHint=true, the description adds value by disclosing the enumeration method (DNS brute-force) and the fields returned. This provides context about the tool's behavior beyond what annotations convey. No contradictions.

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?

Two sentences, no wasted words. First sentence states action and method, second lists outputs and use cases. Front-loaded and efficient.

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 that there is an output schema, the description does not need to explain return values. It covers the tool's method, outputs, and typical uses. Minor omission: no mention that it operates on a single domain only, but overall complete enough.

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% with 'domain' parameter well-described. Description does not add additional meaning to the parameter beyond the schema. Baseline score of 3 is appropriate.

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 title 'Subdomain Discovery' and description clearly state the tool discovers subdomains via DNS brute-force enumeration. It lists specific outputs (names, record types, IPs, status) and use cases, distinguishing it from sibling tools like whois.dns.lookup which perform different DNS operations.

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?

Description mentions use cases (security reconnaissance, asset inventory, infrastructure mapping) but does not specify when to use vs. alternatives like whois.dns.lookup or when not to use (e.g., for single record lookup). No explicit exclusions or alternative guidance.

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