diff --git a/pkg/workflow/compiler_validators.go b/pkg/workflow/compiler_validators.go
index 00753b81fa2..9d11e624775 100644
--- a/pkg/workflow/compiler_validators.go
+++ b/pkg/workflow/compiler_validators.go
@@ -11,6 +11,7 @@ import (
 
 	"github.com/github/gh-aw/pkg/console"
 	"github.com/github/gh-aw/pkg/constants"
+	"github.com/goccy/go-yaml"
 )
 
 // validateExpressions checks expression safety and runtime-import file references
@@ -318,6 +319,12 @@ func (c *Compiler) emitSandboxRuntimeWarnings(workflowData *WorkflowData, markdo
 }
 
 func (c *Compiler) emitGeneralToolWarnings(workflowData *WorkflowData, markdownPath string) {
+	if workflowData.SafeOutputs != nil && hasWorkflowDispatchInputs(workflowData.On) && workflowData.ConcurrencyJobDiscriminator == "" {
+		fmt.Fprintln(os.Stderr, formatCompilerMessage(markdownPath, "warning",
+			"workflow_dispatch workflow has no concurrency.job-discriminator; the generated conclusion concurrency group is shared by all dispatches of this workflow. "+
+				"Set a discriminator (for example, `${{ github.run_id }}`) to give each dispatch its own slot."))
+		c.IncrementWarningCount()
+	}
 	if workflowData.Concurrency != "" && strings.Contains(workflowData.Concurrency, "cancel-in-progress: true") && hasBotSelfCancelRisk(workflowData) {
 		fmt.Fprintln(os.Stderr, formatCompilerMessage(markdownPath, "warning",
 			"Custom workflow-level concurrency with cancel-in-progress: true may cause self-cancellation.\n"+
@@ -362,6 +369,23 @@ func (c *Compiler) emitGeneralToolWarnings(workflowData *WorkflowData, markdownP
 	}
 }
 
+func hasWorkflowDispatchInputs(onYAML string) bool {
+	var parsedData map[string]any
+	if err := yaml.Unmarshal([]byte(onYAML), &parsedData); err != nil {
+		return false
+	}
+	onMap, ok := parsedData["on"].(map[string]any)
+	if !ok {
+		return false
+	}
+	workflowDispatch, ok := onMap["workflow_dispatch"].(map[string]any)
+	if !ok {
+		return false
+	}
+	inputs, ok := workflowDispatch["inputs"].(map[string]any)
+	return ok && len(inputs) > 0
+}
+
 func (c *Compiler) emitExperimentalFeatureWarnings(workflowData *WorkflowData) {
 	c.emitExperimentalFeatureWarningsTo(workflowData, os.Stderr)
 }
diff --git a/pkg/workflow/workflow_dispatch_concurrency_warning_test.go b/pkg/workflow/workflow_dispatch_concurrency_warning_test.go
new file mode 100644
index 00000000000..811abd89dea
--- /dev/null
+++ b/pkg/workflow/workflow_dispatch_concurrency_warning_test.go
@@ -0,0 +1,101 @@
+//go:build !integration
+
+package workflow
+
+import (
+	"testing"
+
+	"github.com/github/gh-aw/pkg/testutil"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestWorkflowDispatchConcurrencyWarning(t *testing.T) {
+	tests := []struct {
+		name          string
+		on            string
+		discriminator string
+		safeOutputs   bool
+		expectWarning bool
+	}{
+		{
+			name:          "workflow dispatch without discriminator",
+			on:            "on: workflow_dispatch",
+			safeOutputs:   true,
+			expectWarning: false,
+		},
+		{
+			name:          "workflow dispatch with empty inputs without discriminator",
+			on:            "on:\n  workflow_dispatch:\n    inputs: {}",
+			safeOutputs:   true,
+			expectWarning: false,
+		},
+		{
+			name:          "workflow dispatch with inputs without discriminator",
+			on:            "on:\n  workflow_dispatch:\n    inputs:\n      target_repo:\n        type: string",
+			safeOutputs:   true,
+			expectWarning: true,
+		},
+		{
+			name:          "workflow dispatch with inputs without safe outputs",
+			on:            "on:\n  workflow_dispatch:\n    inputs:\n      target_repo:\n        type: string",
+			expectWarning: false,
+		},
+		{
+			name:          "mixed workflow dispatch without discriminator",
+			on:            "on:\n  workflow_dispatch:\n  schedule:\n    - cron: '0 0 * * *'",
+			safeOutputs:   true,
+			expectWarning: false,
+		},
+		{
+			name:          "mixed workflow dispatch with inputs without discriminator",
+			on:            "on:\n  workflow_dispatch:\n    inputs:\n      target_repo:\n        type: string\n  schedule:\n    - cron: '0 0 * * *'",
+			safeOutputs:   true,
+			expectWarning: true,
+		},
+		{
+			name:          "workflow dispatch with inputs and discriminator",
+			on:            "on:\n  workflow_dispatch:\n    inputs:\n      target_repo:\n        type: string",
+			discriminator: "${{ github.run_id }}",
+			safeOutputs:   true,
+			expectWarning: false,
+		},
+		{
+			name:          "nested workflow dispatch value without discriminator",
+			on:            "on:\n  workflow_run:\n    workflows: [workflow_dispatch]\n    types: [completed]",
+			safeOutputs:   true,
+			expectWarning: false,
+		},
+		{
+			name:          "schedule without discriminator",
+			on:            "on:\n  schedule:\n    - cron: '0 0 * * *'",
+			safeOutputs:   true,
+			expectWarning: false,
+		},
+	}
+
+	const warning = "workflow_dispatch workflow has no concurrency.job-discriminator"
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			compiler := NewCompiler()
+			workflowData := &WorkflowData{
+				On:                          tt.on,
+				ConcurrencyJobDiscriminator: tt.discriminator,
+			}
+			if tt.safeOutputs {
+				workflowData.SafeOutputs = &SafeOutputsConfig{}
+			}
+
+			output := testutil.CaptureStderr(t, func() {
+				compiler.emitGeneralToolWarnings(workflowData, "test.md")
+			})
+
+			if tt.expectWarning {
+				assert.Contains(t, output, warning)
+				assert.Equal(t, 1, compiler.GetWarningCount())
+			} else {
+				assert.NotContains(t, output, warning)
+				assert.Zero(t, compiler.GetWarningCount())
+			}
+		})
+	}
+}