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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so safety and externality are covered structurally. The description adds that the search spans international lists (a useful data-source hint), but says nothing about match output, timeout/latency, or behavior when no hits are found. With annotations carrying the behavioral load, a 3 is appropriate.

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?

A single sentence, front-loaded with the action and scope, with the input key at the end. Nothing is redundant and no filler is present.

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 one-parameter read-only lookup with full schema coverage and annotations covering safety, the definition is nearly sufficient. It does not describe the shape of a result (hit/miss, matched list, entity details) and no output schema exists to fill that gap, which is the only real omission.

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% — 'inn' is documented as a 10-digit organization tax number with a regex pattern. The description's 'по ИНН' reinforces the required identifier but adds no format or validation detail beyond the schema, so the baseline 3 holds.

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?

The description states a specific verb and resource ('Проверка организации по международным санкционным спискам') and enumerates the concrete sources covered (OFAC, EU, UK), which is real information beyond the tool name. The word 'организации' implicitly separates it from check_sanctions_person, but no sibling is named explicitly, so it stops short of a 5.

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?

Usage is only implied: an agent can infer this is the sanctions screen to run on a legal entity before counterparty onboarding. There is no explicit when-to-use, when-not-to-use, or routing to alternatives such as check_fedsfm_org or check_sanctions_person, so the minimum-viable level applies.

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