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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful context beyond them: pagination and partial-match search behavior, plus a plan/tariff gating caveat ('Отбор по меткам доступен не на всех тарифах') that an agent needs to anticipate failures.

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-loads what the tool returns, then explains the label concept, the companion resource, and the tariff caveat. The middle sentence is dense but every clause carries meaning; no filler.

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 5-parameter read tool with no output schema, the description covers return content (values of a label), how to obtain the required key, search/pagination, and the tariff restriction. Only minor gaps remain, such as return ordering or maximum result size.

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 key, page, search, per_page and quiz_id are already documented in the schema. The description adds the source of 'key' (hidden_options) and confirms search/pagination semantics, but nothing beyond what the schema already conveys, 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 (показывает, какие значения встречались) and resource (значения метки ссылки в ответах опроса), and clarifies what a 'метка' is with concrete examples (utm_source, идентификатор ученика, номер курса). It separates itself from the sibling get_quiz_hidden_options by explaining that one returns names while this returns values, though it references the resource URI rather than the tool name.

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?

Gives a clear workflow: fetch label names from quiz://{id}/hidden_options first, then call this tool to get the values of the chosen name. It also notes the values can be searched and paginated. It does not state explicit when-not-to-use conditions, keeping it just below a 5.

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