dns_lookup

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

No annotations are provided, so the description carries full responsibility. It discloses key behavior: parallel resolution of multiple record types, a default set of common types, and optional type/resolver filtering. It does not mention potential latency or error cases, but for a read-only network lookup, the description is sufficiently transparent.

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: first states the core action and method, second lists returned record types and optional parameters. Every sentence is informative and there is no redundancy.

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 straightforward DNS lookup with a small parameter set, the description covers the purpose, optional parameters, and return content. It does not cover when to prefer specialized sibling tools, but the simplicity of the operation means this is not a critical gap.

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 schema already provides 100% coverage for all three parameters with clear descriptions. The tool description adds minor value by enumerating the default record types and hinting at the 'custom resolver' option, but does not significantly extend what the schema provides.

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 tool's function: resolving all DNS record types for a domain, with an explicit list of record types. The verb 'Resolve' and resource 'domain' are specific, and the tool is distinctly the general lookup tool among many specialized DNS siblings.

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 clear context: this is the general-purpose DNS lookup for all record types, with options to filter by type or use a custom resolver. It does not explicitly reference sibling tools or exclusions, but the scope is evident from the description.

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