calc_ndfl

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

With no annotations provided, the description carries full burden. It discloses 'Side effects: read-only, deterministic, offline; no auth or network.' These are critical behavioral traits. However, it could mention error handling or edge cases (e.g., negative income already handled by schema minimum=0). Still, the key safety and performance aspects are clearly stated.

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?

The description is highly concise: 4 sentences covering purpose, usage guidelines, side effects, and return structure. Every sentence adds value with no redundancy or fluff.

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?

Given the complexity of the tool (progressive tax, 3 parameters, output schema exists), the description covers purpose, when/not to use, side effects, and return fields. It lacks detailed explanation of bracket structure in returns, but since an output schema likely exists, this is acceptable. The legal reference (NK RF art. 224) adds useful context.

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% (all parameters have descriptions). The description reinforces that deductions are subtracted from income and that the result includes per-bracket breakdown, but it does not add significant new meaning beyond the schema. Baseline 3 is appropriate.

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?

Description clearly states 'Progressive personal income tax (NDFL/НДФЛ) 2025+ with per-bracket breakdown' and specifies the resource 'salary or IP income after deductions'. The verb 'estimate annual NDFL' is precise, and the tool is clearly distinguished from siblings like calc_insurance_ip, calc_vat, etc.

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?

Explicitly provides 'When to use' and 'When NOT to use' sections, including an alternative for employer withholding ('use payroll') and a limitation ('non-resident rates not modeled'). This provides clear guidance on when to invoke this tool versus alternatives.

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