Look up DNS records

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and external-network profile is covered. The description usefully adds that DNSSEC status is included alongside the records, but says nothing about timeout, rate limits, or behavior for non-existent domains — modest added value over the structured fields.

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?

A single sentence that front-loads the return value and packs the record enumeration and DNSSEC note with no filler. Every clause earns its place.

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?

With no output schema, the description carries the burden of indicating what is returned, and it does so by naming the record types and DNSSEC status. Given a two-parameter read-only tool, this is nearly complete; only error/empty-result behavior is left implicit.

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 100% and both parameters are documented in the schema, so the baseline is 3. The description restates the record-type list but adds no syntax or format details beyond what the schema already provides; note the description mentions SRV while the schema default list omits it.

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 gives a specific verb ('Returns') plus resource ('DNS records of a host or domain') and enumerates the record types covered, so the agent knows exactly what comes back. It stops short of differentiating itself from near-neighbors like lookup_whois or check_email_domain, which also probe domain metadata.

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?

There is no statement of when to reach for this tool versus alternatives such as inspect_ssl_certificate, lookup_whois, or check_email_domain. Usage is only weakly implied by the record types listed.

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