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

With no annotations provided, the description carries the full burden of behavioral disclosure. It openly describes the return structure and explicitly documents the error case (isError with 'Не найдено' when the slug does not exist). It could additionally state that the operation is read-only with no side effects, but the content makes this clear enough.

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 front-loaded with the core purpose, followed by a compact enumeration of return fields, the error condition, and routing guidance. Every sentence earns its place, and the field list is detailed without being 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?

For a single-parameter lookup with no output schema and no annotations, the description is remarkably complete: it covers the input, return payload, error behavior, and when to prefer sibling tools. An agent can invoke and interpret this tool correctly without additional clarification.

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 baseline is 3. The tool description only restates that lookup is by slug and does not add format examples or constraints beyond what the schema already provides. This is acceptable because the schema fully documents the parameter.

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 opens with 'Одна тематическая подборка каталога по slug', which clearly identifies the tool as a single-category retrieval by slug. It enumerates the specific returned fields, distinguishing it from list_categories (plural) and from search_offers/get_mfo, which it explicitly names.

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 states exactly when to use the tool: when the question matches a ready-made catalog collection, with the example 'микрокредиты пенсионерам'. It also names the alternatives for other cases: search_offers for amount/term-based selection and get_mfo for a full MFO card, leaving no ambiguity about routing.

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