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

Annotations already declare read-only and open-world behavior, so the description appropriately focuses on what they cannot convey: cost, payment mechanics, and returned fields such as TTLs and the DNSSEC validation flag. It does not cover rate limits or non-payment failure modes, but the payment behavior is a meaningful addition.

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?

Two sentences, both front-loaded: the first defines the lookup and returned data, the second covers cost and payment. There is no filler, and the enum list, while long, is relevant to the tool's capability.

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 usefully discloses that responses include TTLs and a DNSSEC validation flag. It also explains the unusual payment model. It could say more about output shape or partial failures, but it is largely complete for a two-parameter lookup tool.

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 coverage is 50%: the domain parameter is described in the schema, while the type parameter is an enum with a default. The description lists the same record types as the enum but does not explain the type parameter's default or add 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 resource and scope: DNS records for a domain over DNS-over-HTTPS, listing the supported record types. It is clearly distinct from domain_whois and domain_report in practice, but it does not explicitly name or contrast those siblings.

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 purpose and by the payment note, but there is no explicit guidance on when to choose this tool over domain_whois or domain_report. No exclusions or alternative-selection conditions are stated.

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