List virtual hosts

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

Annotations already cover readOnlyHint, idempotentHint, and openWorldHint, so the agent knows this is a safe, non-destructive, possibly partial listing. The description adds only the scope 'served by a hosting service', which is a slight enhancement. No additional behavioral context like pagination, ordering, or return format is given, but the annotations mitigate the need.

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, concise sentence that is front-loaded with the action and resource. There is no filler or redundancy, and every word earns its place. It is an exemplary model of brevity.

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 listing tool with rich annotations (read-only, idempotent, open-world), the description is adequate. It specifies the scope and required input context. The lack of an output schema is not a description deficiency, and the agent can reasonably expect a list of domain names. Slightly more detail about the return format would improve completeness, but it is not critical.

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 has 100% description coverage: both userId and hostingId have clear descriptions. The tool description adds no extra parameter information, so it does not go beyond what the schema already provides. The baseline for high schema coverage is 3, and no additional semantics are offered.

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 the verb 'List' and the resource 'virtual hosts', scoped to a hosting service. It distinguishes itself implicitly from sibling tools like ws_hosting_vhost_get (which retrieves a single vhost) and ws_hosting_list (which lists hosting services), but does not explicitly name those alternatives. The purpose is unambiguous and specific.

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?

Usage is implied: to list virtual hosts for a given hosting service, this tool is used. However, there is no explicit guidance on when to choose this over ws_hosting_vhost_get or when not to use it, nor any mention of alternatives. The context is clear enough for an agent to infer, but no exclusions or comparisons are provided.

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