list_passive_dns

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the operation is a 'list' (implying read-only) and reveals domains for an IP, but it does not mention any limits, pagination, or what happens when no results exist. For a simple list operation this is adequate, but it leaves some behavioral traits unspecified.

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 two sentences with zero wasted words. The primary action and resource are stated first, followed by a concise rationale for use. It is appropriately sized and front-loaded.

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 two-parameter tool with full schema coverage and no output schema, the description provides the essential purpose and a use case. However, it lacks explicit usage guidelines (when not to use, alternatives) and any mention of behavioral limitations. Given the low complexity, it is minimally sufficient but not comprehensive.

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?

The input schema already provides full descriptions for both parameters (ip and account_id) at 100% coverage, so the baseline is 3. The description does not add any additional semantic detail beyond the schema; it only ties the ip parameter to the concept of passive DNS. No enhancement is needed, but no extra value is provided either.

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 ('List') and resource ('domains that have resolved to a specific IP address'), and immediately identifies it as passive DNS. It is distinct from sibling tools like get_ip_intel or get_domain_intel, though it does not explicitly name alternatives. The purpose is unambiguous and actionable.

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 a concrete use case ('identifying shared hosting or malicious infrastructure'), which implies when it is useful. However, it does not explicitly say when not to use it or mention alternatives such as get_ip_intel or get_domain_intel that might also provide IP-related intelligence. The guidance is contextual but not prescriptive about choice.

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