Список ключевых фраз

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. The description adds genuinely new behavioral facts: the mandatory-filter requirement enforced by the Yandex Direct API and the fact that Bid/ContextBid come back in account currency, which affects how results must be interpreted.

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, each doing distinct work: what it returns, the validity constraint, and a return-value caveat. The most action-critical fact (the mandatory filter) is placed early with 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?

With 8 optional parameters, no output schema and 100% schema coverage, the description supplies the missing pieces an agent needs before calling: a required filter and bid currency. It could still say more about pagination behavior (limit/offset vs autoPaginate), which is the one notable gap for a list tool.

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% and every parameter carries its own Russian description, so the baseline is 3. The description adds one valuable cross-parameter rule (at least one filter id array is mandatory) that the schema does not express via 'required', plus currency semantics for bid fields, but nothing on fieldNames, limit/offset or autoPaginate interplay.

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 and resource ('Возвращает список ключевых фраз'), which cleanly separates it from list_campaigns, list_ad_groups and list_ads among the siblings. It does not, however, explicitly contrast itself with keyword_action or add_keywords, so the read-vs-write distinction is left to the reader.

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 discloses a hard API constraint — at least one of campaignIds, adGroupIds or ids must be supplied — which tells the agent how to make a valid call. It gives no guidance on when to prefer this listing over keyword_action or how to combine filters, so usage context is only implied.

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