Detect triggers: keyword misuse in compile with actionable error

.github/aw/create-agentic-workflow.md

@@ -573,7 +573,7 @@ Should run when issues are opened or edited
 Based on the parsed requirements, determine:
 
 1. **Workflow ID**: Convert the workflow name to kebab-case (e.g., "Issue Classifier" → "issue-classifier")
-2. **Triggers**: Infer appropriate triggers from the description:
+2. **Triggers**: Infer appropriate triggers from the description. **Always use `on:` as the YAML key** — never use `triggers:` (that is not a valid frontmatter key and will cause a compile error):
    - Issue automation → `on: issues: types: [opened, edited]` (add `workflow_dispatch:` manually if manual runs needed)
    - PR automation → `on: pull_request: types: [opened, synchronize]` (add `workflow_dispatch:` manually if manual runs needed)
    - Scheduled tasks → `on: schedule: daily on weekdays` (prefer weekdays to avoid Monday backlog - workflow_dispatch auto-added for fuzzy schedules only)

pkg/workflow/compiler_orchestrator_frontmatter.go

@@ -71,6 +71,11 @@ func (c *Compiler) parseFrontmatterSection(markdownPath string) (*frontmatterPar
 	// Keep the original frontmatter with markers for YAML generation
 	frontmatterForValidation := c.copyFrontmatterWithoutInternalMarkers(result.Frontmatter)
 
+	// Check if user accidentally used "triggers:" instead of the correct "on:" keyword
+	if _, hasTriggers := frontmatterForValidation["triggers"]; hasTriggers {
+		return nil, fmt.Errorf("%s: invalid frontmatter key 'triggers:' — use 'on:' to define workflow triggers", cleanPath)
+	}
+
 	// Check if "on" field is missing - if so, treat as a shared/imported workflow
 	_, hasOnField := frontmatterForValidation["on"]
 	if !hasOnField {

pkg/workflow/compiler_orchestrator_frontmatter_test.go

@@ -71,6 +71,36 @@ Can be imported
 	assert.True(t, result.isSharedWorkflow, "Should be detected as shared workflow")
 }
 
+// TestParseFrontmatterSection_TriggersInsteadOfOn tests that using "triggers:" gives a helpful error
+func TestParseFrontmatterSection_TriggersInsteadOfOn(t *testing.T) {
+	tmpDir := testutil.TempDir(t, "frontmatter-triggers")
+
+	testContent := `---
+triggers:
+  issues:
+    types: [opened]
+engine: copilot
+permissions:
+  contents: read
+---
+
+# Test Workflow
+
+Content here
+`
+
+	testFile := filepath.Join(tmpDir, "test.md")
+	require.NoError(t, os.WriteFile(testFile, []byte(testContent), 0644))
+
+	compiler := NewCompiler()
+	result, err := compiler.parseFrontmatterSection(testFile)
+
+	require.Error(t, err, "Using 'triggers:' instead of 'on:' should cause error")
+	assert.Nil(t, result)
+	assert.Contains(t, err.Error(), "'triggers:'", "Error should mention the invalid key")
+	assert.Contains(t, err.Error(), "'on:'", "Error should mention the correct key")
+}
+
 // TestParseFrontmatterSection_MissingFrontmatter tests error for no frontmatter
 func TestParseFrontmatterSection_MissingFrontmatter(t *testing.T) {
 	tmpDir := testutil.TempDir(t, "frontmatter-missing")