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

Beyond readOnlyHint and openWorldHint annotations, the description discloses the resolver path, backup resolver, current-resolution semantics, TTL behavior, limitation on authoritative/delegation queries, and payment terms including failed-call charging. This is unusually rich behavioral context for a read-only tool.

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 front-loaded with the core purpose and then adds resolver behavior, limitations, and pricing without wasted phrasing. Each clause contributes useful information for an agent deciding whether and how to call the tool.

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?

Given that an output schema exists and annotations declare read-only/open-world behavior, the description supplies the remaining context an agent needs: live resolver semantics, limitations, and payment model. Nothing critical for correct invocation is missing.

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%, so the input schema already documents both name and types, including the supported record types and default. The description reinforces the record types but adds no meaningful parameter semantics beyond the schema.

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 states a specific verb and resource: retrieving DNS records for a domain, with supported record types and resolver behavior. It is clear what the tool does, but it does not explicitly differentiate itself from DNS-focused siblings such as security_dns_caa_records or security_dns_propagation.

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?

The description gives useful context for when to use it: live current resolution via public resolvers, with an explicit limitation that it does not walk the delegation chain or query authoritative servers directly. It does not name sibling alternatives, so it falls short of fully explicit when/when-not/alternatives guidance.

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