Список почтовых ящиков домена

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

The description contradicts the annotations. It says 'Возвращает список' (returns a list), implying a read-only operation, but the readOnlyHint is false. This is a serious inconsistency. Additionally, the description does not provide other behavioral context such as pagination, rate limits, or authentication requirements.

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 concise, consisting of two sentences that clearly state the action and when to use it. No unnecessary words or repetition.

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 the tool's simplicity (one parameter, no output schema), the description covers the core purpose and usage. However, the annotation contradiction undermines completeness, and details like output shape or potential edge cases are absent. The API v1 mention adds useful context.

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 coverage is 100%, with the domain parameter already fully described in the schema (including the example). The tool description adds no additional meaning beyond noting the domain scope, so the baseline of 3 applies.

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 ('Возвращает список') and resource ('почтовых ящиков указанного домена'), clearly stating the tool's scope. It distinguishes itself from sibling tools like list_mailboxes by specifying the domain filter.

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 states when to use the tool: 'Используй, когда нужны только ящики конкретного домена' (use when you need only mailboxes of a specific domain). It provides a clear usage condition, though it does not explicitly mention alternatives or exclusions, which would earn a 5.

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