diff --git a/web/app/components/evaluation/components/metric-section/__tests__/index.spec.tsx b/web/app/components/evaluation/components/metric-section/__tests__/index.spec.tsx
index b7cb0780d8..4fb22e7595 100644
--- a/web/app/components/evaluation/components/metric-section/__tests__/index.spec.tsx
+++ b/web/app/components/evaluation/components/metric-section/__tests__/index.spec.tsx
@@ -48,14 +48,17 @@ describe('MetricSection', () => {
   // Verify the extracted builtin metric card presentation and removal flow.
   describe('Builtin Metric Card', () => {
     it('should render node badges for a builtin metric and remove it when delete is clicked', () => {
+      // Arrange
       act(() => {
         useEvaluationStore.getState().addBuiltinMetric(resourceType, resourceId, 'answer-correctness', [
           { node_id: 'node-answer', title: 'Answer Node', type: 'llm' },
         ])
       })
 
+      // Act
       renderMetricSection()
 
+      // Assert
       expect(screen.getByText('Answer Correctness')).toBeInTheDocument()
       expect(screen.getByText('Answer Node')).toBeInTheDocument()
 
@@ -66,14 +69,40 @@ describe('MetricSection', () => {
     })
 
     it('should render the all-nodes label when a builtin metric has no node selection', () => {
+      // Arrange
       act(() => {
         useEvaluationStore.getState().addBuiltinMetric(resourceType, resourceId, 'answer-correctness', [])
       })
 
+      // Act
       renderMetricSection()
 
+      // Assert
       expect(screen.getByText('evaluation.metrics.nodesAll')).toBeInTheDocument()
     })
+
+    it('should collapse and expand the node section when the metric header is clicked', () => {
+      // Arrange
+      act(() => {
+        useEvaluationStore.getState().addBuiltinMetric(resourceType, resourceId, 'answer-correctness', [
+          { node_id: 'node-answer', title: 'Answer Node', type: 'llm' },
+        ])
+      })
+
+      // Act
+      renderMetricSection()
+
+      const toggleButton = screen.getByRole('button', { name: 'evaluation.metrics.collapseNodes' })
+      fireEvent.click(toggleButton)
+
+      // Assert
+      expect(screen.queryByText('Answer Node')).not.toBeInTheDocument()
+      expect(screen.getByRole('button', { name: 'evaluation.metrics.expandNodes' })).toBeInTheDocument()
+
+      fireEvent.click(screen.getByRole('button', { name: 'evaluation.metrics.expandNodes' }))
+
+      expect(screen.getByText('Answer Node')).toBeInTheDocument()
+    })
   })
 
   // Verify the extracted custom metric editor card renders inside the metric card.
diff --git a/web/app/components/evaluation/components/metric-section/builtin-metric-card.tsx b/web/app/components/evaluation/components/metric-section/builtin-metric-card.tsx
new file mode 100644
index 0000000000..ece7c35892
--- /dev/null
+++ b/web/app/components/evaluation/components/metric-section/builtin-metric-card.tsx
@@ -0,0 +1,101 @@
+'use client'
+
+import type { EvaluationMetric, EvaluationResourceProps } from '../../types'
+import { useState } from 'react'
+import { useTranslation } from 'react-i18next'
+import Button from '@/app/components/base/button'
+import { cn } from '@/utils/classnames'
+import { useEvaluationStore } from '../../store'
+import { getMetricVisual, getNodeVisual, getToneClasses } from '../metric-selector/utils'
+
+type BuiltinMetricCardProps = EvaluationResourceProps & {
+  metric: EvaluationMetric
+}
+
+const BuiltinMetricCard = ({
+  resourceType,
+  resourceId,
+  metric,
+}: BuiltinMetricCardProps) => {
+  const { t } = useTranslation('evaluation')
+  const updateBuiltinMetric = useEvaluationStore(state => state.addBuiltinMetric)
+  const removeMetric = useEvaluationStore(state => state.removeMetric)
+  const [isExpanded, setIsExpanded] = useState(true)
+  const metricVisual = getMetricVisual(metric.optionId)
+  const metricToneClasses = getToneClasses(metricVisual.tone)
+
+  return (
+    <div className="group overflow-hidden rounded-xl border border-components-panel-border hover:bg-background-section">
+      <div className="flex items-center justify-between gap-3 px-3 pb-1 pt-3">
+        <button
+          type="button"
+          className="flex min-w-0 flex-1 items-center gap-2 px-1 text-left"
+          aria-expanded={isExpanded}
+          aria-label={isExpanded ? t('metrics.collapseNodes') : t('metrics.expandNodes')}
+          onClick={() => setIsExpanded(current => !current)}
+        >
+          <div className={cn('flex h-[18px] w-[18px] shrink-0 items-center justify-center rounded-[5px]', metricToneClasses.soft)}>
+            <span aria-hidden="true" className={cn(metricVisual.icon, 'h-3.5 w-3.5')} />
+          </div>
+          <div className="flex min-w-0 items-center gap-0.5">
+            <div className="truncate text-text-secondary system-md-medium">{metric.label}</div>
+            <span
+              aria-hidden="true"
+              className={cn('i-ri-arrow-down-s-line h-4 w-4 shrink-0 text-text-quaternary transition-transform', !isExpanded && '-rotate-90')}
+            />
+          </div>
+        </button>
+
+        <Button
+          size="small"
+          variant="ghost"
+          aria-label={t('metrics.remove')}
+          className="h-6 w-6 shrink-0 rounded-md p-0 text-text-quaternary opacity-0 transition-opacity hover:text-text-secondary focus-visible:opacity-100 group-hover:opacity-100"
+          onClick={() => removeMetric(resourceType, resourceId, metric.id)}
+        >
+          <span aria-hidden="true" className="i-ri-delete-bin-line h-4 w-4" />
+        </Button>
+      </div>
+
+      {isExpanded && (
+        <div className="flex flex-wrap gap-1 px-3 pb-3 pt-1">
+          {metric.nodeInfoList?.length
+            ? metric.nodeInfoList.map((nodeInfo) => {
+                const nodeVisual = getNodeVisual(nodeInfo)
+                const nodeToneClasses = getToneClasses(nodeVisual.tone)
+
+                return (
+                  <div
+                    key={nodeInfo.node_id}
+                    className="inline-flex min-w-[18px] items-center rounded-lg border-[0.5px] border-components-panel-border-subtle bg-components-badge-white-to-dark p-1.5 shadow-xs"
+                  >
+                    <div className={cn('flex h-[18px] w-[18px] shrink-0 items-center justify-center rounded-md border-[0.45px] border-divider-subtle shadow-xs shadow-shadow-shadow-3', nodeToneClasses.solid)}>
+                      <span aria-hidden="true" className={cn(nodeVisual.icon, 'h-3.5 w-3.5')} />
+                    </div>
+                    <span className="px-1 text-text-primary system-xs-regular">{nodeInfo.title}</span>
+                    <button
+                      type="button"
+                      className="flex h-4 w-4 items-center justify-center rounded-sm text-text-quaternary transition-colors hover:text-text-secondary"
+                      aria-label={nodeInfo.title}
+                      onClick={() => updateBuiltinMetric(
+                        resourceType,
+                        resourceId,
+                        metric.optionId,
+                        metric.nodeInfoList?.filter(item => item.node_id !== nodeInfo.node_id) ?? [],
+                      )}
+                    >
+                      <span aria-hidden="true" className="i-ri-close-line h-3.5 w-3.5" />
+                    </button>
+                  </div>
+                )
+              })
+            : (
+                <span className="px-1 text-text-tertiary system-xs-regular">{t('metrics.nodesAll')}</span>
+              )}
+        </div>
+      )}
+    </div>
+  )
+}
+
+export default BuiltinMetricCard
diff --git a/web/app/components/evaluation/components/metric-section/custom-metric-card.tsx b/web/app/components/evaluation/components/metric-section/custom-metric-card.tsx
new file mode 100644
index 0000000000..e327ffbf63
--- /dev/null
+++ b/web/app/components/evaluation/components/metric-section/custom-metric-card.tsx
@@ -0,0 +1,63 @@
+'use client'
+
+import type { EvaluationMetric, EvaluationResourceProps } from '../../types'
+import { useTranslation } from 'react-i18next'
+import Badge from '@/app/components/base/badge'
+import Button from '@/app/components/base/button'
+import { cn } from '@/utils/classnames'
+import { isCustomMetricConfigured, useEvaluationStore } from '../../store'
+import CustomMetricEditorCard from '../custom-metric-editor-card'
+import { getToneClasses } from '../metric-selector/utils'
+
+type CustomMetricCardProps = EvaluationResourceProps & {
+  metric: EvaluationMetric
+}
+
+const CustomMetricCard = ({
+  resourceType,
+  resourceId,
+  metric,
+}: CustomMetricCardProps) => {
+  const { t } = useTranslation('evaluation')
+  const removeMetric = useEvaluationStore(state => state.removeMetric)
+  const isCustomMetricInvalid = !isCustomMetricConfigured(metric)
+  const metricToneClasses = getToneClasses('indigo')
+
+  return (
+    <div className="group overflow-hidden rounded-xl border border-components-panel-border hover:bg-background-section">
+      <div className="flex items-center justify-between gap-3 px-3 pb-1 pt-3">
+        <div className="flex min-w-0 flex-1 items-center gap-2 px-1">
+          <div className={cn('flex h-[18px] w-[18px] shrink-0 items-center justify-center rounded-[5px]', metricToneClasses.soft)}>
+            <span aria-hidden="true" className="i-ri-equalizer-2-line h-3.5 w-3.5" />
+          </div>
+          <div className="truncate text-text-secondary system-md-medium">{metric.label}</div>
+        </div>
+
+        <div className="flex shrink-0 items-center gap-1">
+          {isCustomMetricInvalid && (
+            <Badge className="badge-warning">
+              {t('metrics.custom.warningBadge')}
+            </Badge>
+          )}
+          <Button
+            size="small"
+            variant="ghost"
+            aria-label={t('metrics.remove')}
+            className="h-6 w-6 shrink-0 rounded-md p-0 text-text-quaternary opacity-0 transition-opacity hover:text-text-secondary focus-visible:opacity-100 group-hover:opacity-100"
+            onClick={() => removeMetric(resourceType, resourceId, metric.id)}
+          >
+            <span aria-hidden="true" className="i-ri-delete-bin-line h-4 w-4" />
+          </Button>
+        </div>
+      </div>
+
+      <CustomMetricEditorCard
+        resourceType={resourceType}
+        resourceId={resourceId}
+        metric={metric}
+      />
+    </div>
+  )
+}
+
+export default CustomMetricCard
diff --git a/web/app/components/evaluation/components/metric-section/index.tsx b/web/app/components/evaluation/components/metric-section/index.tsx
index f9f8ccc33b..70a9606ee5 100644
--- a/web/app/components/evaluation/components/metric-section/index.tsx
+++ b/web/app/components/evaluation/components/metric-section/index.tsx
@@ -30,9 +30,6 @@ const MetricSection = ({
             resourceType={resourceType}
             resourceId={resourceId}
             metric={metric}
-            nodesAllLabel={t('metrics.nodesAll')}
-            removeLabel={t('metrics.remove')}
-            customWarningLabel={t('metrics.custom.warningBadge')}
           />
         ))}
         <MetricSelector
diff --git a/web/app/components/evaluation/components/metric-section/metric-card.tsx b/web/app/components/evaluation/components/metric-section/metric-card.tsx
index a1ddc55c32..b066420998 100644
--- a/web/app/components/evaluation/components/metric-section/metric-card.tsx
+++ b/web/app/components/evaluation/components/metric-section/metric-card.tsx
@@ -1,135 +1,34 @@
 'use client'
 
 import type { EvaluationMetric, EvaluationResourceProps } from '../../types'
-import Badge from '@/app/components/base/badge'
-import Button from '@/app/components/base/button'
-import { Tooltip, TooltipContent, TooltipTrigger } from '@/app/components/base/ui/tooltip'
-import { cn } from '@/utils/classnames'
-import { isCustomMetricConfigured, useEvaluationStore } from '../../store'
-import CustomMetricEditorCard from '../custom-metric-editor-card'
-import { getMetricVisual, getNodeVisual, getToneClasses } from '../metric-selector/utils'
+import BuiltinMetricCard from './builtin-metric-card'
+import CustomMetricCard from './custom-metric-card'
 
 type MetricCardProps = EvaluationResourceProps & {
   metric: EvaluationMetric
-  nodesAllLabel: string
-  removeLabel: string
-  customWarningLabel: string
 }
 
 const MetricCard = ({
   resourceType,
   resourceId,
   metric,
-  nodesAllLabel,
-  removeLabel,
-  customWarningLabel,
 }: MetricCardProps) => {
-  const updateBuiltinMetric = useEvaluationStore(state => state.addBuiltinMetric)
-  const removeMetric = useEvaluationStore(state => state.removeMetric)
-  const metricVisual = metric.kind === 'custom-workflow'
-    ? { icon: 'i-ri-equalizer-2-line', tone: 'indigo' as const }
-    : getMetricVisual(metric.optionId)
-  const metricToneClasses = getToneClasses(metricVisual.tone)
-  const isCustomMetricInvalid = metric.kind === 'custom-workflow' && !isCustomMetricConfigured(metric)
-  const hasSelectedNodes = metric.kind === 'builtin' && !!metric.nodeInfoList?.length
+  if (metric.kind === 'custom-workflow') {
+    return (
+      <CustomMetricCard
+        resourceType={resourceType}
+        resourceId={resourceId}
+        metric={metric}
+      />
+    )
+  }
 
   return (
-    <div
-      className={cn(
-        'overflow-hidden rounded-xl border border-components-panel-border',
-        hasSelectedNodes ? 'bg-background-section' : 'bg-components-card-bg',
-      )}
-    >
-      <div className="flex items-center justify-between gap-3 px-3 pb-1 pt-3">
-        <div className="flex min-w-0 flex-1 items-center gap-2 px-1">
-          <div className={cn('flex h-[18px] w-[18px] shrink-0 items-center justify-center rounded-[5px]', metricToneClasses.soft)}>
-            <span aria-hidden="true" className={cn(metricVisual.icon, 'h-3.5 w-3.5')} />
-          </div>
-          <div className="flex min-w-0 items-center gap-1">
-            <div className="truncate text-text-secondary system-md-medium">{metric.label}</div>
-            {metric.description && (
-              <Tooltip>
-                <TooltipTrigger
-                  render={(
-                    <button
-                      type="button"
-                      className="flex h-4 w-4 shrink-0 items-center justify-center text-text-quaternary transition-colors hover:text-text-tertiary"
-                      aria-label={metric.label}
-                    >
-                      <span aria-hidden="true" className="i-ri-question-line h-3.5 w-3.5" />
-                    </button>
-                  )}
-                />
-                <TooltipContent>
-                  {metric.description}
-                </TooltipContent>
-              </Tooltip>
-            )}
-          </div>
-        </div>
-        <div className="flex shrink-0 items-center gap-1">
-          {isCustomMetricInvalid && (
-            <Badge className="badge-warning">
-              {customWarningLabel}
-            </Badge>
-          )}
-          <Button
-            size="small"
-            variant="ghost"
-            aria-label={removeLabel}
-            onClick={() => removeMetric(resourceType, resourceId, metric.id)}
-          >
-            <span aria-hidden="true" className="i-ri-delete-bin-line h-4 w-4" />
-          </Button>
-        </div>
-      </div>
-
-      {metric.kind === 'builtin' && (
-        <div className="flex flex-wrap gap-1 px-3 pb-3 pt-1">
-          {metric.nodeInfoList?.length
-            ? metric.nodeInfoList.map((nodeInfo) => {
-                const nodeVisual = getNodeVisual(nodeInfo)
-                const nodeToneClasses = getToneClasses(nodeVisual.tone)
-
-                return (
-                  <div
-                    key={nodeInfo.node_id}
-                    className="inline-flex min-w-[18px] items-center rounded-lg border-[0.5px] border-components-panel-border-subtle bg-components-badge-white-to-dark p-1.5 shadow-xs"
-                  >
-                    <div className={cn('flex h-[18px] w-[18px] shrink-0 items-center justify-center rounded-md border-[0.45px] border-divider-subtle shadow-xs shadow-shadow-shadow-3', nodeToneClasses.solid)}>
-                      <span aria-hidden="true" className={cn(nodeVisual.icon, 'h-3.5 w-3.5')} />
-                    </div>
-                    <span className="px-1 text-text-primary system-xs-regular">{nodeInfo.title}</span>
-                    <button
-                      type="button"
-                      className="flex h-4 w-4 items-center justify-center rounded-sm text-text-quaternary transition-colors hover:text-text-secondary"
-                      aria-label={nodeInfo.title}
-                      onClick={() => updateBuiltinMetric(
-                        resourceType,
-                        resourceId,
-                        metric.optionId,
-                        metric.nodeInfoList?.filter(item => item.node_id !== nodeInfo.node_id) ?? [],
-                      )}
-                    >
-                      <span aria-hidden="true" className="i-ri-close-line h-3.5 w-3.5" />
-                    </button>
-                  </div>
-                )
-              })
-            : (
-                <span className="px-1 text-text-tertiary system-xs-regular">{nodesAllLabel}</span>
-              )}
-        </div>
-      )}
-
-      {metric.kind === 'custom-workflow' && (
-        <CustomMetricEditorCard
-          resourceType={resourceType}
-          resourceId={resourceId}
-          metric={metric}
-        />
-      )}
-    </div>
+    <BuiltinMetricCard
+      resourceType={resourceType}
+      resourceId={resourceId}
+      metric={metric}
+    />
   )
 }
 
diff --git a/web/i18n/en-US/evaluation.json b/web/i18n/en-US/evaluation.json
index 9fb4198bb0..a691f99fa2 100644
--- a/web/i18n/en-US/evaluation.json
+++ b/web/i18n/en-US/evaluation.json
@@ -52,6 +52,7 @@
   "metrics.add": "Add Metric",
   "metrics.addCustom": "Add Custom Metrics",
   "metrics.added": "Added",
+  "metrics.collapseNodes": "Collapse nodes",
   "metrics.custom.addMapping": "Add Mapping",
   "metrics.custom.description": "Select an evaluation workflow and map your variables before running tests.",
   "metrics.custom.footerDescription": "Connect your published evaluation workflows",
@@ -65,6 +66,7 @@
   "metrics.custom.workflowLabel": "Evaluation Workflow",
   "metrics.custom.workflowPlaceholder": "Select a workflow",
   "metrics.description": "Choose from built-in metrics like Groundedness and Correctness to evaluate your workflow outputs.",
+  "metrics.expandNodes": "Expand nodes",
   "metrics.groups.operations": "Operations",
   "metrics.groups.other": "Other",
   "metrics.groups.quality": "Quality",