Excel Finance MCP

Instructions

Implementation Reference

• src/python/tax_calculations.py:156-211 (handler)

  Main handler function implementing the depreciation deduction calculation logic for different methods: Section 179, MACRS (calling helper), and Straight Line.
  def calculate_depreciation_deduction(self, asset_id: str, tax_year: int) -> Dict[str, float]: """Calculate depreciation deduction for an asset""" asset = self.assets.get(asset_id) if not asset: return {'error': 'Asset not found'} years_in_service = tax_year - asset.placed_in_service_date.year if asset.depreciation_method == DepreciationMethod.SECTION_179: # Section 179 immediate expensing (2024 limit: $1,220,000) section_179_limit = 1220000 deduction = min(asset.cost, section_179_limit) return { 'asset_id': asset_id, 'depreciation_method': 'Section 179', 'annual_deduction': deduction, 'remaining_basis': 0, 'total_depreciation': deduction } elif asset.depreciation_method == DepreciationMethod.MACRS: # MACRS depreciation from financial_calculations import DepreciationCalculator macrs_schedule = DepreciationCalculator.macrs(asset.cost, asset.useful_life) if years_in_service < len(macrs_schedule): annual_deduction = macrs_schedule[years_in_service] total_depreciation = sum(macrs_schedule[:years_in_service + 1]) else: annual_deduction = 0 total_depreciation = sum(macrs_schedule) return { 'asset_id': asset_id, 'depreciation_method': 'MACRS', 'annual_deduction': round(annual_deduction, 2), 'remaining_basis': round(asset.cost - total_depreciation, 2), 'total_depreciation': round(total_depreciation, 2) } elif asset.depreciation_method == DepreciationMethod.STRAIGHT_LINE: annual_deduction = asset.cost / asset.useful_life total_depreciation = annual_deduction * min(years_in_service + 1, asset.useful_life) return { 'asset_id': asset_id, 'depreciation_method': 'Straight Line', 'annual_deduction': round(annual_deduction, 2), 'remaining_basis': round(asset.cost - total_depreciation, 2), 'total_depreciation': round(total_depreciation, 2) } return {'error': 'Unknown depreciation method'}
• src/tools/tax-tools.ts:167-174 (schema)

  Input schema validation for the tool parameters: assetId (string, required) and taxYear (number, required).
  inputSchema: { type: "object", properties: { assetId: { type: "string" }, taxYear: { type: "number" } }, required: ["assetId", "taxYear"] },
• src/tools/tax-tools.ts:164-190 (registration)

  MCP tool registration including name, description, input schema, and TypeScript handler that invokes the Python implementation via bridge.
  { name: "calculate_depreciation_deduction", description: "Calculate tax depreciation deduction for an asset", inputSchema: { type: "object", properties: { assetId: { type: "string" }, taxYear: { type: "number" } }, required: ["assetId", "taxYear"] }, handler: async (args: any): Promise<ToolResult> => { try { const result = await pythonBridge.callPythonFunction({ module: 'tax_calculations', function: 'TaxCalculator.calculate_depreciation_deduction', args: [args.assetId, args.taxYear] }); return result; } catch (error) { return { success: false, error: error instanceof Error ? error.message : String(error) }; } } },
• src/python/financial_calculations.py:210-223 (helper)

  Helper function called by the main handler for MACRS depreciation schedule calculation using predefined rates for 3,5,7,10 year recovery periods.
  def macrs(cost: float, recovery_period: int) -> List[float]: """Calculate MACRS depreciation (simplified)""" macrs_rates = { 3: [0.3333, 0.4445, 0.1481, 0.0741], 5: [0.2000, 0.3200, 0.1920, 0.1152, 0.1152, 0.0576], 7: [0.1429, 0.2449, 0.1749, 0.1249, 0.0893, 0.0892, 0.0893, 0.0446], 10: [0.1000, 0.1800, 0.1440, 0.1152, 0.0922, 0.0737, 0.0655, 0.0655, 0.0656, 0.0655, 0.0328] } if recovery_period not in macrs_rates: raise ValueError(f"MACRS rates not available for {recovery_period} year period") rates = macrs_rates[recovery_period] return [cost * rate for rate in rates]