VirusTotal domain lookup

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

Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so the safety profile is covered. The description adds genuine context beyond that: which fields are returned (detection ratio, reputation, registrar, creation date, category tags) and the analytic insight that a recent creation date is a newly-registered-domain signal. It does not discuss rate limits or quota behavior, which is the main remaining gap.

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?

Front-loaded with the core action, then the indicator-assessment context, then the return summary. Every sentence is relevant, though the enumeration of returned fields is slightly long and could be trimmed.

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?

Given a 1-param schema at full coverage, rich annotations, and an existing output schema, the description is close to complete: it says what is looked up, why, and roughly what comes back. Only missing element is explicit routing against the sibling lookup/scan tools.

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?

There is a single parameter with 100% schema description coverage ('A domain name, e.g. example.com'), so the schema already carries the parameter meaning. The description adds no format or syntax detail beyond it, which matches the baseline 3 for high-coverage schemas.

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 ('Look up') and resource ('a domain on VirusTotal') and is clearly differentiated from siblings like lookup_ip, lookup_hash, and scan_url. The second sentence enumerates exactly what is being assessed, so an agent can tell which indicator type this tool covers without opening the schema.

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?

Explicitly frames when to call it: 'to assess a *domain* indicator' and 'when pivoting from a URL or email sender to the domain behind it.' That gives a clear usage context, but it never names the alternative siblings (e.g., scan_url for raw URLs) or states when not to use it.

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