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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful context about the authoritative data source (Росфинмониторинг terrorist/extremist list), but says nothing about what a result looks like or how matches are reported, which is a real gap for a boolean-style check with no output schema.

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 front-loaded sentence with zero filler; the resource and the key parameter are stated immediately.

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 simple one-parameter read-only lookup whose schema and annotations are complete, the description is minimally adequate. However, with no output schema it never explains what the check returns (hit/miss, match details), leaving a gap an agent would want filled.

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%: the single 'inn' parameter already carries type, required flag, a 10-digit pattern and a description. The description only restates "по ИНН" without adding format, normalization, or error-handling detail, 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?

The description names a specific verb (проверка) and resource (организация по перечню террористов и экстремистов Росфинмониторинга) plus the key input (ИНН), making the purpose unambiguous. It implicitly distinguishes itself from check_fedsfm_person via "организации", but never explicitly routes against the many other check_*_org siblings, so it falls 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?

The description provides no when-to-use guidance, no exclusions, and does not name any alternative (e.g., check_fedsfm_person, check_sanctions_org). The intended usage is only inferable from the tool name and its registry-specific wording.

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