dns.lookup

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

No annotations are provided, so the description carries the full behavioral burden. It implies a network DNS query and mentions a custom nameserver, but it omits timeout behavior, failure modes, response shape, and whether it contacts a remote resolver. This is minimal disclosure for an unannotated network 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 a single concise fragment with no wasted words and the key record-type list is front-loaded. However, its fragmentary structure and extreme brevity leave important information unstated, making it concise at the expense of usefulness.

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?

There is no output schema and no annotations, and the description does not explain result format, errors, or how record type selection affects the response. For a DNS lookup tool with eight record types and a nameserver override, the definition is substantially incomplete.

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 0%, so the description must compensate for all three parameters. It lists the record types and nameserver override, but does not explain the required name parameter, the default record value of A, or the fact that nameserver must be an IPv4/IPv6 address.

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 operation: a DNS lookup for several record types with an optional nameserver override. It is clear enough to identify the tool's function, but it does not distinguish it from siblings such as dns.reverse or dns.propagation, especially because PTR is also listed as a record type here.

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 no when-to-use guidance, no prerequisites, and no comparison to alternatives like dns.reverse, dns.resolvers, or dns.propagation. The only contextual hint is the optional nameserver override, which is too thin to guide tool selection.

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