НДФЛ по прогрессивной шкале

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

Annotations already declare readOnly=true, idempotent=true, destructive=false, so the safety profile is covered. The description still adds value by clarifying scope boundaries: it is 'только вычисление' and explicitly does not model deductions or alternative tax scales. It stops short of richer notes (e.g. rounding behavior), so not a 5.

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?

Front-loaded with the core purpose and rate table, then the call modes, then sibling routing, then exclusions. Every clause earns its place; no filler despite the longer length.

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?

No output schema exists, yet the description explains what is returned (bracket-by-bracket breakdown and effective rate), and the two input modes are fully disambiguated. Nothing needed to invoke it 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 description coverage is 100%, with both income and income_before fully documented, so the baseline is 3. The description echoes income_before semantics (tax computed on the single payment given prior-year-to-date income) but adds no syntax or edge-case detail beyond the schema.

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 precise verb+resource (calculates NDFL for a resident on work income under the 2025–2026 progressive scale) and even enumerates the brackets. It explicitly distinguishes itself from the sibling salary_calc for full-salary calculations, so an agent can route without opening schemas.

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?

Names the alternative ('Для зарплаты целиком удобнее salary_calc') and then states explicit exclusions: no deductions and no other-scale income (dividends, deposits, property sales). When-to-use, when-to-use-something-else, and when-not-at-all are all covered.

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