vat-calculation

name	vat-calculation
description	This skill should be used when the user wants to "calculate VAT", "compute value-added tax", "算增值税", "计算应缴增值税", "增值税计算", "帮我算增值税", "VAT计算", "进项销项税额计算", "增值税应纳税额", "抵扣后增值税". It collects sales amount, VAT rate, and input tax, then computes the exact payable VAT with a risk assessment and filing recommendations.
when_to_use	Activate when the user needs a deterministic VAT calculation, not a general policy explanation. The skill: collects parameters → calls tax_calculator tool for exact figures → validates compliance → returns a structured summary with payable amount and risk flags. NOT for general questions about VAT policy — answer those directly from domain knowledge.
metadata	{"author":"internal-tax-team","version":"1.0","domain":"tax"}
compatibility	Requires: python3 Tools: tax_calculator, tax_compliance_checker, execute_python
allowed-tools	Bash Read

VAT Calculation Skill

Overview

Guide the user through a precise, auditable VAT (增值税) calculation. Follow the collect → calculate → validate → report workflow.

All calculations use the tax_calculator tool — never compute tax amounts from memory.

Workflow

Step 1: Collect Required Parameters

Ask the user (or extract from context):

Parameter	Chinese	Required	Default	Validation
sales_amount	含税销售额	✅	—	> 0
vat_rate	增值税率	✅	0.13	one of 0.13 / 0.09 / 0.06 / 0.03 / 0.01
input_vat	进项税额	optional	0.0	>= 0

If the user provides a rate as a percentage (e.g. "13%"), convert to decimal (0.13). If the user says "一般纳税人" without specifying a rate, default to 0.13. If the user says "小规模纳税人", use 0.03.

Step 2: Calculate Using Tool

Call tax_calculator with tax_type="vat":

{
  "tax_type": "vat",
  "sales_amount": <collected value>,
  "vat_rate": <collected value>,
  "input_vat": <collected value or 0>
}

The tool returns:

• output_vat — 销项税额
• input_vat — 进项税额 (echo)
• payable_vat — 应缴增值税（= 销项 - 进项）
• risk_issues — 合规风险提示列表
• recommendations — 建议列表

Step 3: Compliance Check (if risk_issues non-empty)

If the tool returns any risk_issues, call tax_compliance_checker for a full compliance report:

{
  "tax_data": {
    "vat": {
      "rate": <vat_rate>,
      "output_vat": <output_vat>,
      "input_vat": <input_vat>
    }
  },
  "tenant_id": "<tenant_id from context>"
}

Step 4: Present Result

Show a structured summary:

增值税计算结果
==============
销售额（含税）：¥{sales_amount:,.2f}
增值税率：      {vat_rate*100:.0f}%
销项税额：      ¥{output_vat:,.2f}
进项税额：      ¥{input_vat:,.2f}
────────────────────────────────
应缴增值税：    ¥{payable_vat:,.2f}

{risk_summary}
{recommendations}

免责声明：以上计算仅供参考，具体以税务机关认定为准。

If payable_vat < 0, show: "存在留抵税额 ¥{abs(payable_vat):,.2f}，可结转下期抵扣。"

Step 5: Follow-up

Ask if the user wants to:

• 计算企业所得税（推荐使用 corporate-tax-check 技能）
• 查询最新增值税政策（调用 search_web）
• 导出计算明细（用 execute_python 格式化并输出 CSV）

Error Handling

• Invalid rate: If user provides a rate not in {0.01, 0.03, 0.06, 0.09, 0.13}, warn them: "该税率不在法定范围内（1%/3%/6%/9%/13%），请确认业务类型。"
• sales_amount = 0: Ask "请提供具体的销售额，无法对零金额计算。"
• Tool failure: Fall back to execute_python with the formula directly: output_vat = sales_amount * vat_rate; payable_vat = output_vat - input_vat

Gotchas

• 含税销售额 ≠ 不含税销售额。本技能使用含税销售额直接乘以税率（简易计税法）。 若用户提供的是不含税销售额，提示区别并换算。
• 小规模纳税人通常无进项抵扣资格（3%税率），若 input_vat > 0 请提示风险。
• 出口退税、免税销售等特殊场景超出本技能范围，提示用户咨询专业人士。