Создание почтового ящика (API v1)

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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the description does not need to repeat that. It adds the contextual detail that this is an API v1 endpoint intended for compatibility, which is useful but not a deep behavioral disclosure. No contradictions with annotations, but there is no mention of side effects, permissions, or return behavior beyond the write operation.

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 two short sentences, front-loaded with the primary purpose and immediately followed by the critical usage guidance. There is zero waste; every word earns its place.

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 that this is a compatibility shim and the schema covers all parameters, the description provides enough context: it states the action, the API version, and the preference for the v2 alternative. It does not detail return values, but no output schema is provided and the tool is simple enough that this is acceptable. The explicit warning to prefer v2 makes the tool's role fully clear.

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%, so each parameter (domain, mailbox, password, comment) is already well-documented. The description does not add any parameter-level semantics beyond what the schema provides, so a baseline score 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 clearly states the tool's function ('Создаёт почтовый ящик') with a specific verb and resource. It immediately distinguishes itself from the sibling tool create_mailbox by mentioning 'API v1' and explicitly stating it is only for compatibility, making it one of the clearest purpose statements.

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 provides when-to-use guidance: 'Предпочитай create_mailbox (v2) — этот нужен только для совместимости' (Prefer create_mailbox (v2) — this one is needed only for compatibility). This directly names the alternative and states the condition for using this tool, which is excellent usage guidance.

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