Resolve domain (DNS)

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the safety profile is covered. The description adds useful non-obvious context: results are public addresses only (external DNS), and the target domain has already been resolved in the investigation flow. No mention of rate limits or resolver behavior, but that is secondary given annotations.

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 short sentences, front-loaded with the action and output type, followed by the routing rule. Every clause earns its place with no filler.

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 does at least state the return type (IPv4/IPv6 addresses), which is the key missing piece. However, the unexplained 'investigation_id' parameter leaves a real hole for a tool that is presumably meant to attach results to an existing investigation.

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% for both parameters, and the description mentions neither. 'domain' is inferable from the name, but 'investigation_id' is entirely undocumented — its purpose, whether it is required in practice, and what changes when it is supplied are all left to guesswork.

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?

States a specific verb and resource ('Resolve a domain') plus the exact output shape ('its public IPv4/IPv6 addresses'), which distinguishes it from sibling tools like shodan_search or subdomains. An agent knows immediately what this does.

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?

Gives real routing guidance: 'Already run for a domain target; use it for other domains you discover' tells the agent not to re-resolve the primary target and to use it on newly surfaced domains. It stops short of naming a sibling alternative for the primary-target case, so not a 5.

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