dns_lookup

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

With no annotations provided, the description carries the full burden. It usefully discloses the default record set and the optional nameserver override, but it does not describe the output format, failure behavior, or whether the query is recursive/authoritative. Partial but not comprehensive disclosure.

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, front-loaded with the core purpose and immediately useful defaults. No filler or redundant restatement of the tool name.

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 simple 3-parameter tool with no output schema and no annotations, the description covers basic invocation and default behavior. It is missing explicit semantics for record_types and return format, but an agent can still make a reasonable basic call.

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. It adds meaning for nameserver with an example and communicates the default record types, which informs how record_types behaves. However, it does not explicitly explain the record_types parameter or list all accepted values, leaving a gap.

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 ('DNS records for a domain') and lists the default record types, making the tool's core function clear. It doesn't explicitly differentiate it from siblings like recon_domain or domain_whois, but the DNS-record focus is distinct enough.

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 implies usage when DNS records are needed and explains how to query a specific resolver. However, it does not mention when not to use it or name alternatives for broader recon or WHOIS lookups, leaving some routing decisions to the agent.

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