Query URLhaus threat intelligence to find malicious URLs hosted on a specific domain. Identify known abuse associated with a hostname.
Get information about URLs hosted on a specific host/domain
| Name | Required | Description | Default |
|---|---|---|---|
| host | Yes | The hostname or domain to look up (e.g., "example.com") |
| Name | Required | Description | Default |
|---|---|---|---|
| summary | Yes | ||
| host_info | Yes | ||
| urls_count | Yes | ||
| query_status | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already declare readOnlyHint=true, so the non-mutating behavior is covered structurally. The description adds minimal context beyond the host/domain scope and does not disclose details like result limits, pagination, or whether the lookup only returns current URLs. It is consistent with the annotations and adds no contradicting behavior.
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 a single sentence with no filler, front-loading the action and object. It is appropriately sized for a one-parameter, read-only lookup tool and every word contributes to clarity.
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, read-only, one-parameter tool with a full output schema and 100% schema coverage, the description is complete enough for an agent to invoke it correctly. The annotations cover the safety profile, and the schema covers the parameter and output structure, so no additional explanation is required.
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 the parameter description already provides a clear meaning with an example ('example.com'). The tool description merely restates 'host/domain' without adding additional semantics. With full schema coverage, the baseline of 3 is appropriate.
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 uses a specific verb and resource: 'Get information about URLs hosted on a specific host/domain'. This clearly conveys a host-scoped lookup and helps distinguish it from sibling tools like lookup_url, which implies URL-level lookup. However, it does not explicitly name or contrast sibling tools, so it falls just short of 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 description implies the tool is appropriate when an agent has a hostname or domain and wants associated URL information. It provides no explicit guidance about when to prefer this tool over alternatives such as lookup_url or get_urls_by_tag, nor does it state when not to use it. The usage context is inferable but not stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.