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

With no annotations, the description carries the full burden and does so well: it discloses error semantics (isError with «Не найдено»), null semantics (first_loan_zero_percent null = unconfirmed), data provenance (license_registry_url as primary legality source) and record freshness. It omits auth/rate-limit context, so not a 5.

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?

Front-loaded with purpose, then return fields, error behavior and the terms sub-fields. It is dense and long, but every clause documents returnable fields that have no output schema to carry them, so the length is largely justified.

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 output schema, the description must explain the return payload, and it does so thoroughly: conditions, summary, requirements, commissions, rating, legal data, update date, plus the nested terms fields and error case. An agent has everything needed to call and interpret it.

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 the single slug parameter is fully documented in the schema, including format and source. The description adds no syntax or format detail beyond that, so the baseline 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?

States a specific verb+resource and scope: 'Полная карточка одной МФО по slug'. It is clearly distinguishable from list_mfo (enumeration) and get_reviews (reviews), and the description even delegates reviews to that sibling explicitly.

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?

Explicitly routes reviews to get_reviews and instructs citing canonical_url when using the data. The schema adds where to obtain slug (list_mfo, search_offers, get_category). No explicit when-not-to-use guidance for list_mfo, but the context is clear.

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