search_virustotal

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

With no annotations, the description carries the full burden and does well: it discloses the required VIRUSTOTAL_API_KEY env var, the side effect of URL submission (VirusTotal fetches the URL and exposes it to the community), and that this active mode is off by default. Rate limits and quota behavior are not mentioned, and no output/return format is described.

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?

Three dense sentences, front-loaded with purpose and the input-type list, then the environment prerequisite, then the passive/active distinction. Every sentence adds information; nothing is redundant with the schema.

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 two-parameter lookup tool with no output schema and no annotations, the description covers auth, accepted inputs, and the important active-mode side effect. The main omission is any hint of what a result contains or how large/expensive a query can be, which matters given an external API quota.

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 coverage is 50%: json_output is documented in the schema, but target is bare. The description compensates by enumerating the accepted input types (IP, domain, URL, file hash) and noting that the type is auto-detected, so an agent knows what to pass without guessing a format prefix.

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 (check/scan) and resource (IP, domain, URL, file hash) against a named service, and the '70+ antivirus engines and threat intelligence' phrasing distinguishes it from geolocation/DNS/WHOIS siblings in the same search_* family.

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?

Explains that input type is auto-detected and clearly separates the default passive lookup from the opt-in active URL submission mode, which is genuine when-to-use guidance. It does not, however, route the agent to alternatives like search_abuseipdb or search_shodan for overlapping IP/domain reputation needs.

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