net-mcp

Dns Lookup

dns_lookup

Query DNS records for any domain and verify DNSSEC validation status. Use it to check DNS configuration, identify validation failures, and troubleshoot resolution issues with clear pass/fail results.

Instructions

Query DNS records for a domain with DNSSEC validation status.

Returns the requested records along with whether DNSSEC is enabled and whether validation passes. Use this to check DNS configuration and DNSSEC health for any domain.

If the resolver returns SERVFAIL (which a validating resolver does when DNSSEC validation fails), this re-queries with the CD (Checking Disabled) bit to distinguish a genuine DNSSEC failure from an unrelated server error.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`name`	Yes	Domain name to query (e.g. 'cloudflare.com')
`resolver`	No	DNS resolver IP to use. Defaults to the configured resolver.
`record_type`	No	DNS record type: A, AAAA, MX, NS, TXT, SOA, CNAME, PTR, SRV, CAA, DNSKEY, DS (case-insensitive)	A

Output Schema

TableJSON Schema

Name	Required	Description
`dnssec`	Yes	DNSSEC status of the answer
`records`	Yes	Answer records (empty if none)
`resolver`	Yes	Resolver IP the query was sent to
`query_name`	Yes	Name that was queried
`query_type`	Yes	Record type that was queried
`response_time_ms`	Yes	Round-trip time in milliseconds

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 22, 2026

TDQS

A4.5/5.0

Behavior5/5

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

With no annotations, the description carries full behavioral burden and succeeds admirably. It explains return contents (records, DNSSEC enabled, validation passes), the SERVFAIL handling, and the CD-bit re-query strategy, which is materially useful for interpreting results.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact and front-loaded: purpose and use case come first, then the important edge-case behavior. Every sentence adds value, especially the SERVFAIL/CD-bit explanation, with no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the moderate complexity, full schema coverage, and presence of an output schema, the description is complete. It covers purpose, usage context, return semantics, and a subtle failure-mode behavior, leaving no critical gap for an agent to invoke it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all three parameters well. The description does not add parameter-level semantics beyond referring to 'requested records,' which is acceptable but not an improvement over the baseline.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'Query DNS records for a domain with DNSSEC validation status.' It clearly distinguishes this tool from generic DNS tools like dns_trace or local_dig by uniquely mentioning DNSSEC validation status and fallback behavior.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives a direct use case: 'Use this to check DNS configuration and DNSSEC health for any domain.' It does not explicitly list when-not-to-use or name alternative tools, but the intended context is clear.

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