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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description contributes only the point-in-time nature of the result ('на дату'); it says nothing about permissions, rate limits, or what the returned status values mean.

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 a clarifying parenthetical for 'самозанятого'; no filler or redundancy. Every element (subject, key, date scope) earns its place.

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 and no annotation describing the return, so the description could have stated what status outcomes to expect (e.g. is/is not registered as self-employed). For a two-parameter status lookup this is a noticeable but minor gap.

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% – the format of inn (12 digits) and date (yyyy-mm-dd, defaults to today) is fully documented in the schema. The description merely restates 'по ИНН физлица на дату', adding no syntax or interpretation beyond it, which is the expected baseline.

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 resource (статус плательщика НПД / самозанятого), the lookup key (ИНН физлица) and the temporal scope (на дату), so the agent knows exactly what is checked. It does not explicitly contrast itself with any sibling, but no other check_* tool covers the self-employment registry, so confusion risk is low.

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?

There is no statement of when to use this tool versus the many sibling check_* tools (налог, банкротство, санкции, дисквалификация) nor any prerequisite or exclusion. The agent must infer from the name alone that this is the self-employed-status check.

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