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

With no annotations provided, the description carries the burden of behavioral disclosure. It usefully communicates the cost ('Costs $0.001 USDC on Base per call') and the response shape, but it does not mention error conditions, rate limits, payment prerequisites, or that a network/paid call is made.

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 dense sentences cover purpose, supported record types, request/response shape, and cost. Every clause is informative, and the core purpose is front-loaded before the payment note.

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?

The definition is adequate for a simple lookup: it names input and output shapes and discloses cost. However, it omits practical call context such as how payment is handled, error behavior, and when to choose this over the sibling domain_whois, which leaves some gaps for an agent.

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 schema already documents both parameters and the default value. The description adds little beyond restating the body shape ('Body {domain, type?}'), which is already implied by 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 clearly states a specific verb ('lookup') and resource ('DNS-over-HTTPS lookup' for a defined set of record types), making the core function obvious. It is distinguishable from the sibling domain_whois by its focus on DNS records rather than registration data, though it does not explicitly name the alternative.

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 given about when to use this tool versus alternatives like domain_whois. The description implies it is for resolving DNS records, but it provides no exclusions, prerequisites, or explicit use-case context.

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