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

Annotations only cover readOnlyHint=true, so the description carries most of the burden — and it delivers: it discloses the exact field set returned and, importantly, that seller identity and contacts are NOT returned and messaging must happen in-app. The one gap is no note on error behavior for an unknown id.

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, front-loaded with the payload, then the trigger condition, then the hard limitation. No redundancy or 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?

There is no output schema, so the description must describe the return surface — and it does, both positively (fields returned) and negatively (seller info withheld). Nothing an agent needs to call this 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?

Schema coverage is 100% and the id description ('UUID объявления из search_listings') already documents origin and format. The prose adds nothing about the parameter beyond that, 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 ('Показать') and resource ('одно объявление Tapuzinski') and enumerates the returned fields (заголовок, описание, цену, состояние, ссылки на фото). It is clearly distinguishable from list_taxonomy and search_listings by being the single-item detail fetch.

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?

Explicitly places itself in the flow relative to a sibling: 'Зови после search_listings, когда человек выбрал вещь и хочет подробностей'. That is a clear triggering condition and an implied alternative, though it does not state an explicit when-not-to-use case.

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