Check whether a URL appears in the URLhaus database as a malware distribution site to identify potential threats.
Check if a URL is listed as a malware distribution site in the URLhaus database.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | The URL to look up |
Changes observed during successful MCP inspections.
v0.1.11Does 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 no extra context such as rate limits, whether a negative result is authoritative, or what the response contains.
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?
A single front-loaded sentence that wastes no words. Nothing is padded, though it could have used the remaining space for a routing hint.
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 one-param read tool with no output schema, the definition is workable but leaves the return shape (verdict only vs full threat details) and negative-result semantics unstated, which matters for a lookup tool.
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 100% and there is only one parameter, so the schema already documents 'url' fully. The description adds no format expectations (scheme required, hostname vs full URL) beyond what the schema states.
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) and resource (URL against the URLhaus malware-distribution dataset), so an agent immediately knows what it does. It does not distinguish itself from related siblings such as virustotal_url_report, urlscan_search, or urlhaus_recent, which keeps it from a 5.
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 mention of the URLhaus database implies the context (threat-intel blocklist check) but never says when to use this instead of virustotal_url_report or urlscan, and offers no exclusions or prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.