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

No annotations exist, so the description carries the full burden. It usefully discloses the outcome and its privilege level ("В ответе токен scope checkout"), which is real added context. But it says nothing about invalid-code behavior, token lifetime, or how the returned token is used downstream — gaps that matter for a session-creating 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?

Three short sentences: purpose, credential guidance, output. The action is front-loaded and every clause carries information an agent would otherwise have to guess.

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 three-parameter auth tool with no output schema, the description covers what to send and what comes back, including the token scope. Missing are failure modes and token lifecycle, but the essentials for a correct call are present.

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 coverage is 100%, so a 3 is the baseline, and the description earns an extra point by stating the either/or relationship between code and password — an exclusivity constraint the schema does not express via oneOf or similar. The required phone parameter is only covered by 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 verb and object are explicit ("Завершить вход" = finish/complete login) and the description distinguishes the two credential paths (code vs password). It never names the sibling request_login_code, so the pairing with the code-issuing step is left implicit rather than spelled out.

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?

It gives clear context: call it once the client has received a code and reported it back, or when they want to sign in with a password. Nothing is said about when not to call it (e.g. before request_login_code, or with both fields) and no sibling is named.

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