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

The description is consistent with the annotations (readOnlyHint, idempotentHint, destructiveHint=false) but adds no behavioral context beyond them. It does not mention default behavior, caching, response shape, or error conditions. The annotations carry the safety profile, but no extra transparency is provided.

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 with no unnecessary words, front-loading the verb and the full list of supported record types. It is immediately scannable and contains no filler.

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 simple two-parameter read-only lookup, the core usage is clear, and the annotations cover the safety profile. However, the description does not state what happens if 'types' is omitted, and there is no output schema to clarify the return structure. Sibling tools cover related DNS areas, so a brief scope statement would improve completeness.

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 documents both parameters with 100% coverage. The description adds value by listing the valid record types for the 'types' parameter, which the schema only describes generically as 'comma-separated record types.' It does not explain defaults or exact formatting beyond that.

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 uses a specific verb ('Resolve') and clearly names the resource: DNS records for a domain, enumerating exact record types. It is easy to tell this is a current DNS lookup tool, though it does not explicitly contrast with sibling tools like dns_history or dns_profile.

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 provided about when to use dns_lookup versus siblings such as dns_history, dns_compare, or dns_profile. The phrase 'resolve records' implies current-record lookup, but there are no explicit exclusions or alternative routing instructions.

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