Cian Offer Card

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely useful behavior beyond that: a full failure taxonomy (BadRequestError, NotFoundError, TransportDownError on WAF/CDP, ParserDriftError) and the semantic rule that price_rub is None rather than 0 when unstated.

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 purpose sentence followed by clearly sectioned Return Format and Error Format blocks; every line carries information. The exhaustive field enumeration leans long relative to the existing output schema, which is the only mild redundancy.

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 an output schema present, annotations covering safety, and full parameter coverage, the description is close to self-sufficient: it explains the payload, the null-vs-zero price rule, and the failure modes. The only gap is absent guidance on tool selection relative to cian_search.

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 the single parameter is documented in the schema as 'Cian offer id (digits) or a full cian.ru offer URL.' The description only echoes this indirectly via the BadRequest error case, so it adds little beyond the schema — 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 and resource — 'Read one Cian offer' — and enumerates the payload (price history, layout, building, address, metro, publisher). The word 'one' scopes it to a single-offer lookup, which distinguishes it from the sibling cian_search without needing to be spelled out.

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?

Use case is implied by 'Read one offer' plus the required offer_id_or_url parameter. However, there is no explicit when-to-use statement, no mention of when to prefer cian_search, and no note about prerequisites (e.g. needing an ID from a prior search).

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