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

There are no annotations, so the description carries full responsibility. It discloses the not-found behavior (isError with «Не найдено»), explains the semantics of the top field, and explicitly instructs agents to use the precomputed tops instead of performing their own sorting. This is substantial behavioral context beyond the schema.

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 and then gives a dense but purposeful breakdown of return fields and usage routing. It is long, but every clause contributes meaning, and the length is justified because there is no output schema to carry return-structure documentation.

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 one required parameter, no output schema, and no annotations, the description covers the response fields, error handling, sorting semantics, and sibling-tool routing. Nothing an agent needs in order to select and invoke this tool correctly is missing.

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?

The single slug parameter has 100% schema description coverage, including format, an example URL, and the instruction to take the slug from list_categories. The tool description itself adds no additional parameter detail, so the baseline of 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?

The description opens with a precise verb+resource statement: «Одна тематическая подборка каталога по slug», then lists the returned fields. It clearly distinguishes this tool from siblings by naming the alternatives for other use cases, e.g., search_offers for filtering by amount/term and get_mfo for full MFO cards.

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?

The description explicitly states when to use the tool: «Используйте, когда вопрос совпадает с готовой подборкой», gives a concrete example («микрокредиты пенсионерам»), and routes to specific sibling tools for adjacent cases. This leaves no ambiguity about selection.

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