dns_lookup

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

With no annotations, the description carries the full burden and discloses meaningful behavior: it uses DoH, returns every answer with its TTL, and distinguishes NXDOMAIN from a missing record type. It does not cover all edge cases, such as handling of unsupported types, but the core response semantics are clear.

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 with no filler: the action is front-loaded, the accepted record types are compactly listed, and the output behavior is stated in a single clause. Every sentence earns its place.

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 two-parameter lookup with no output schema, the description is sufficiently complete: it names the input, enumerates valid types, and describes both the success return (answers with TTL) and the no-answer distinction. An agent has enough to invoke it correctly and interpret results.

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 100%, so the baseline is 3; the description adds value by enumerating the valid record types for the type parameter, which the schema does not. It reinforces the name parameter's role without duplicating the schema's hostname examples.

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 opens with a specific verb and resource: "Resolve a DNS name over DNS-over-HTTPS." It enumerates supported record types, which makes the tool's function clear, though it does not explicitly contrast itself with siblings like reverse_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 through the record-type list and the hostname example, but there is no explicit statement of when to choose this tool over alternatives like reverse_dns, dnsbl_check, or lookup_port. No exclusion criteria or recommended contexts are given.

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