user_auth_post

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

Annotations are absent, so the description carries the full behavioral burden. It reveals only that a session_id is produced; it does not mention credential handling, whether the call is idempotent, rate limits, or the rw-mode preview behavior (which the schema's 'confirm' param alludes to but the description never explains).

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?

It is short, but the content is boilerplate metadata ('POST /user/auth', 'Тег: Пользователи', 'Спека: user') rather than agent-useful information. The purpose is also not front-loaded; the raw HTTP path comes first and the tag/spec lines earn no 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?

With no annotations, no output schema and a nested request body, the description should clarify credential placement, the rw-mode confirmation requirement, and what the session_id is used for. It supplies none of this, leaving the agent to infer the entire authentication contract.

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 the schema already documents login, password, confirm and user_id. The description adds no parameter-level meaning beyond that, making the baseline 3 the correct score.

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 Russian line 'Авторизация (получение session_id)' does state a specific verb (authorization) and a concrete outcome (obtaining a session_id). However, with siblings like user_password_auth_post, user_auth_passkey_post and user_telegram_web_auth_post sitting right next to it, the definition gives no clue which authentication mechanism this endpoint covers, so an agent cannot distinguish it from its peers.

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?

There is no when-to-use, when-not-to-use, or prerequisite guidance. Nothing tells the agent how user_auth_post differs from user_password_auth_post or the passkey/telegram auth variants, nor when this flow should be preferred.

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