List Webmaster hosts

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

With readOnlyHint annotation already present, the description adds valuable behavioral context: it lists response fields, explains the optional hostId behavior that fetches a host summary, and notes the host_id dependency. It does not discuss auth or rate limits, but that is not expected here given the annotations and simple scope.

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 sentences, front-loaded with 'Discovery tool,' and no filler. Every sentence adds value—purpose, output contents, optional parameter behavior, and usage order.

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 one optional parameter, no output schema, and simple scope, the description is complete: it names the returned fields, explains the optional summary, and positions the tool as the first call. No important aspect is missing for the agent to select and invoke it correctly.

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 schema already fully documents hostId, including optionality and behavior. The description reiterates that behavior without adding new syntax or format details. However, it reinforces the hostId's importance by noting that other tools need it, which is useful context beyond the schema.

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 'sites (hosts) available to your Yandex Webmaster token,' with specific output details (host_id, URL, verification state). It establishes this as the discovery tool and distinguishes it from sibling tools by saying 'Call this first' and explaining host_id is needed by every other tool.

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 explicitly says 'Call this first' and explains that host_id is required by other tools, giving clear context for when to use it. It does not name alternative tools or explicitly state when not to use it, but the guidance is strong enough to earn a 4.

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