Function generateToolInputSchema

apps/sim/lib/mcp/workflow-tool-schema.ts:139–188

(inputFormat: InputFormatField[])

 * that MCP clients can use to understand tool parameters.
 */
export function generateToolInputSchema(inputFormat: InputFormatField[]): McpToolInputSchema {
  const properties: Record<string, McpToolProperty> = {}
  const required: string[] = []

  for (const field of inputFormat) {
    if (!field.name) continue

    const fieldName = field.name
    const fieldType = mapFieldTypeToJsonSchemaType(field.type)

    const property: McpToolProperty = {
      type: fieldType,
      // Use custom description if provided, otherwise use field name
      description: field.description?.trim() || fieldName,
    }

    // Handle array types
    if (fieldType === 'array') {
      if (field.type === 'file[]') {
        property.items = {
          type: 'object',
          properties: {
            name: { type: 'string', description: 'File name' },
            url: { type: 'string', description: 'File URL' },
            type: { type: 'string', description: 'MIME type' },
            size: { type: 'number', description: 'File size in bytes' },
          },
        }
        // Use custom description if provided, otherwise use default
        if (!field.description?.trim()) {
          property.description = 'Array of file objects'
        }
      } else {
        property.items = { type: 'string' }
      }
    }

    properties[fieldName] = property

    // All fields are considered required by default
    // (in the future, we could add an optional flag to InputFormatField)
    required.push(fieldName)
  }

  return {
    type: 'object',
    properties,
    required: required.length > 0 ? required : undefined,
  }
}

/**
 * Overlay sparse per-parameter description overrides onto a base schema produced by