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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered and the bar is lower. The description adds no behavioral context beyond that — no note on resolver latency, rate limits, or failure modes (e.g. NXDOMAIN, timeouts) that a DNS query tool would plausibly exhibit.

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 tight sentence with the action front-loaded and no filler. Every clause (record types, domain, resolver) carries information.

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 three-parameter read-only tool with full schema coverage and enum documentation, the description is complete enough to invoke correctly. The only minor gap is that no return shape is hinted at, though the absence of an output schema makes that less critical.

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 the schema already documents defaults for type (A) and server (cloudflare) plus the enum sets. The description merely restates the record types and mentions a chosen resolver, adding no syntax or constraint detail beyond the schema, so baseline 3 applies.

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?

States a specific verb (Query) and resource (DNS records) and enumerates the supported record types, which distinguishes it from siblings like whois_lookup or ip_lookup. It does not, however, explicitly contrast itself with dns_domain_ready or domain_report, which also touch DNS.

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?

Usage is implied by the clear purpose, but there is no explicit statement of when to use this versus sibling resolver tools (dns_domain_ready, domain_report), nor any exclusions or prerequisites. Adequate but leaves routing to inference.

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