dns_lookupResolve a hostname to its IP addresses. Returns address records for the given host.
Resolve a hostname to addresses.
| Name | Required | Description | Default |
|---|---|---|---|
| host | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.8.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already indicate a read-only operation (readOnlyHint=true) and external world access (openWorldHint=true). The description adds no behavioral context beyond restating the core function, such as reliance on DNS servers, possible timeouts, multiple address records, or error behavior.
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, efficient sentence with no filler. The verb is front-loaded, and every word contributes to meaning. It is appropriately sized for a tool of this simplicity.
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, read-only, and has an output schema, so the description covers the basics. However, it lacks any guidance on when to reach for this tool over related network tools and does not describe output characteristics such as address families or failure cases. It is minimally viable but leaves room for useful context.
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 single required parameter has no schema description (0% coverage), but the description clarifies that 'host' expects a hostname rather than a URL or raw IP. This provides minimal semantic value, though it does not specify format details like whether FQDNs, trailing dots, or protocol prefixes are accepted.
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 a specific verb ('Resolve') and resource ('a hostname') with a concrete result ('to addresses'). It is recognizable as a DNS lookup, but it does not explicitly differentiate itself from sibling tools like network_check or host_identity.
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?
No guidance is given about when to use this tool versus alternatives such as web_search, network_check, or http_fetch. The intended usage is only implied by the tool's name and terse description, and no exclusions or follow-up tools are mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.