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

Annotations already declare readOnlyHint and openWorldHint, but the description adds substantive context: the check is free, the return is a set of findings graded fail/warn/ok/info, and a check_id may be returned that feeds create_checkout. It also adds a privacy constraint ('Не передавайте персональные данные: нужен только адрес сайта') that no structured field conveys. Missing only operational details such as latency or rate limits.

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, front-loaded with purpose, then return shape and handoff, then the safety constraint. Every sentence carries information an agent needs and nothing is padded.

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 only two parameters and no output schema, the description covers the gap by explaining the return values (severity-graded findings and an optional check_id) and the data-handling constraint. An agent has everything needed to call it and interpret the result.

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% and both parameters carry descriptions, including the enum meaning for mode, so the schema does the heavy lifting. The description only reinforces that the URL alone is required; it adds no new syntax or format detail beyond the schema, making the baseline 3 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 names a specific verb and resource ('Бесплатно проверяет сайт') and scopes it to two concrete purposes: 152-FZ compliance and payment-provider readiness. It also positions the tool relative to a sibling by naming the create_checkout handoff, so an agent can tell what this tool does and what it does not do.

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 explicit triggering contexts ('по 152-ФЗ или перед подключением приёма оплаты') and a follow-up path ('check_id для create_checkout'), which is enough for correct selection. It stops short of stating when not to use it or contrasting with get_offer, so a 4 rather than a 5.

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