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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and scope are covered. The description adds genuinely new behavioral context — «Отдаёт только публичные объявления: без продавца, без контактов и без точного адреса» — telling the agent what the result set will and will not contain, which is critical for privacy-sensitive answers.

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?

Two sentences, zero filler: purpose first, then call conditions, then return scoping. Every clause earns its place and nothing is buried.

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 10-param, no-output-schema search tool, the description covers purpose, triggers and result boundaries. It omits any mention of pagination (limit/offset) and sort defaults, but those are documented in the schema, so coverage is adequate rather than fully self-contained.

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 80%, so city, category, max_price, query, radius and sort are already documented inline. The description only loosely maps trigger phrases to those filters and adds no syntax, defaults, or format detail 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 (найти/поиск) and resource (объявления) and scopes it precisely: hyperlocal marketplace Tapuzinski, Израиль, б/у вещи. An agent can separate this from get_listing (single ad) and list_taxonomy (slug lookup) without opening any schema.

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?

«Зови, когда человек спрашивает, что продаётся рядом с конкретным городом, по категории, до какой-то цены или по свободному описанию вещи» gives explicit trigger conditions covering the main query shapes. It lacks an explicit negative case or a pointer to get_listing for a known listing, so it stops short of full routing guidance.

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