diff --git a/apps/sim/lib/copilot/tools/server/workflow/edit-workflow/builders.test.ts b/apps/sim/lib/copilot/tools/server/workflow/edit-workflow/builders.test.ts
new file mode 100644
index 000000000..a83a7efd4
--- /dev/null
+++ b/apps/sim/lib/copilot/tools/server/workflow/edit-workflow/builders.test.ts
@@ -0,0 +1,44 @@
+/**
+ * @vitest-environment node
+ */
+import { describe, expect, it, vi } from 'vitest'
+import { createBlockFromParams } from './builders'
+
+const agentBlockConfig = {
+  type: 'agent',
+  name: 'Agent',
+  outputs: {
+    content: { type: 'string', description: 'Default content output' },
+  },
+  subBlocks: [{ id: 'responseFormat', type: 'response-format' }],
+}
+
+vi.mock('@/blocks/registry', () => ({
+  getAllBlocks: () => [agentBlockConfig],
+  getBlock: (type: string) => (type === 'agent' ? agentBlockConfig : undefined),
+}))
+
+describe('createBlockFromParams', () => {
+  it('derives agent outputs from responseFormat when outputs are not provided', () => {
+    const block = createBlockFromParams('b-agent', {
+      type: 'agent',
+      name: 'Agent',
+      inputs: {
+        responseFormat: {
+          type: 'object',
+          properties: {
+            answer: {
+              type: 'string',
+              description: 'Structured answer text',
+            },
+          },
+          required: ['answer'],
+        },
+      },
+      triggerMode: false,
+    })
+
+    expect(block.outputs.answer).toBeDefined()
+    expect(block.outputs.answer.type).toBe('string')
+  })
+})
diff --git a/apps/sim/lib/copilot/tools/server/workflow/edit-workflow/builders.ts b/apps/sim/lib/copilot/tools/server/workflow/edit-workflow/builders.ts
index 935e7bcee..21e71edfa 100644
--- a/apps/sim/lib/copilot/tools/server/workflow/edit-workflow/builders.ts
+++ b/apps/sim/lib/copilot/tools/server/workflow/edit-workflow/builders.ts
@@ -1,7 +1,7 @@
 import crypto from 'crypto'
 import { createLogger } from '@sim/logger'
 import type { PermissionGroupConfig } from '@/lib/permission-groups/types'
-import { getBlockOutputs } from '@/lib/workflows/blocks/block-outputs'
+import { getEffectiveBlockOutputs } from '@/lib/workflows/blocks/block-outputs'
 import { buildCanonicalIndex, isCanonicalPair } from '@/lib/workflows/subblocks/visibility'
 import { getAllBlocks } from '@/blocks/registry'
 import type { BlockConfig } from '@/blocks/types'
@@ -54,7 +54,10 @@ export function createBlockFromParams(
         subBlocks[key] = { id: key, type: 'short-input', value: value }
       })
     }
-    outputs = getBlockOutputs(params.type, subBlocks, triggerMode)
+    outputs = getEffectiveBlockOutputs(params.type, subBlocks, {
+      triggerMode,
+      preferToolOutputs: !triggerMode,
+    })
   } else {
     outputs = {}
   }
diff --git a/apps/sim/lib/workflows/defaults.ts b/apps/sim/lib/workflows/defaults.ts
index d93dd0b13..7de0c058a 100644
--- a/apps/sim/lib/workflows/defaults.ts
+++ b/apps/sim/lib/workflows/defaults.ts
@@ -1,4 +1,4 @@
-import { getBlockOutputs } from '@/lib/workflows/blocks/block-outputs'
+import { getEffectiveBlockOutputs } from '@/lib/workflows/blocks/block-outputs'
 import { getBlock } from '@/blocks'
 import type { BlockConfig, SubBlockConfig } from '@/blocks/types'
 import type { BlockState, SubBlockState, WorkflowState } from '@/stores/workflows/workflow/types'
@@ -85,7 +85,10 @@ function buildStartBlockState(
     subBlockValues[config.id] = initialValue ?? null
   })
 
-  const outputs = getBlockOutputs(blockConfig.type, subBlocks)
+  const outputs = getEffectiveBlockOutputs(blockConfig.type, subBlocks, {
+    triggerMode: false,
+    preferToolOutputs: true,
+  })
 
   const blockState: BlockState = {
     id: blockId,
diff --git a/apps/sim/stores/workflows/utils.ts b/apps/sim/stores/workflows/utils.ts
index 03039b7f8..c63e67053 100644
--- a/apps/sim/stores/workflows/utils.ts
+++ b/apps/sim/stores/workflows/utils.ts
@@ -1,7 +1,7 @@
 import type { Edge } from 'reactflow'
 import { v4 as uuidv4 } from 'uuid'
 import { DEFAULT_DUPLICATE_OFFSET } from '@/lib/workflows/autolayout/constants'
-import { getBlockOutputs } from '@/lib/workflows/blocks/block-outputs'
+import { getEffectiveBlockOutputs } from '@/lib/workflows/blocks/block-outputs'
 import { mergeSubblockStateWithValues } from '@/lib/workflows/subblocks'
 import { TriggerUtils } from '@/lib/workflows/triggers/triggers'
 import { getBlock } from '@/blocks'
@@ -188,7 +188,10 @@ export function prepareBlockState(options: PrepareBlockStateOptions): BlockState
     })
   }
 
-  const outputs = getBlockOutputs(type, subBlocks, triggerMode)
+  const outputs = getEffectiveBlockOutputs(type, subBlocks, {
+    triggerMode,
+    preferToolOutputs: !triggerMode,
+  })
 
   return {
     id,