fix: render validation.checks instead of nonexistent validation.output

src/fixtures/review-validation-failed.json

@@ -0,0 +1,74 @@
+{
+  "review": {
+    "reviewScore": 18
+  },
+  "validation": {
+    "checks": [
+      {
+        "name": "skill_md_line_count",
+        "status": "passed",
+        "message": "SKILL.md line count is 171 (<= 500)",
+        "details": {
+          "line_count": 171,
+          "max_lines": 500
+        }
+      },
+      {
+        "name": "frontmatter_valid",
+        "status": "passed",
+        "message": "YAML frontmatter is valid",
+        "details": {
+          "keys": ["name", "description"]
+        }
+      },
+      {
+        "name": "name_field",
+        "status": "passed",
+        "message": "'name' field is valid: 'legibility-review'",
+        "details": {
+          "value": "legibility-review",
+          "length": 17
+        }
+      },
+      {
+        "name": "description_field",
+        "status": "error",
+        "message": "'description' must not contain XML tags",
+        "details": {
+          "length": 915
+        }
+      },
+      {
+        "name": "body_present",
+        "status": "passed",
+        "message": "SKILL.md body is present",
+        "details": {
+          "body_chars": 17335
+        }
+      }
+    ],
+    "overallPassed": false,
+    "errorCount": 1,
+    "warningCount": 0,
+    "skillName": "legibility-review",
+    "skillDescription": "How to review code so a reader without your context can understand each piece."
+  },
+  "contentJudge": {
+    "success": true,
+    "evaluation": {
+      "scores": {
+        "conciseness": {
+          "score": 0,
+          "reasoning": "Deterministic validation failed; LLM judge was not run."
+        }
+      },
+      "overall_assessment": "Skill failed deterministic validation. LLM judge evaluation was skipped.",
+      "suggestions": [
+        "Fix the deterministic validation errors before running LLM judge."
+      ],
+      "validation_skipped": true
+    },
+    "weightedScore": 0,
+    "normalizedScore": 0
+  }
+}

src/main.test.ts

@@ -258,7 +258,23 @@ describe('runSkillReview', () => {
         normalizedScore: 0.85,
         evaluation: 'Good skill definition.',
       },
-      validation: { output: 'All checks passed.' },
+      validation: {
+        checks: [
+          {
+            name: 'frontmatter_valid',
+            status: 'passed',
+            message: 'YAML frontmatter is valid',
+          },
+          {
+            name: 'body_present',
+            status: 'passed',
+            message: 'SKILL.md body is present',
+          },
+        ],
+        overallPassed: true,
+        errorCount: 0,
+        warningCount: 0,
+      },
     });
 
     // @ts-expect-error mock assignment
@@ -269,10 +285,35 @@ describe('runSkillReview', () => {
     expect(result.score).toBe(85);
     expect(result.passed).toBe(true);
     expect(result.error).toBeUndefined();
-    expect(result.output).toContain('All checks passed.');
+    expect(result.output).toContain('### Validation Checks');
+    expect(result.output).toContain('Validation passed');
+    expect(result.output).toContain('YAML frontmatter is valid');
+    expect(result.output).toContain('SKILL.md body is present');
     expect(result.output).toContain('Good skill definition.');
   });
 
+  test('renders failing validation checks from golden fixture', async () => {
+    const fixture = await Bun.file(
+      new URL('./fixtures/review-validation-failed.json', import.meta.url),
+    ).text();
+
+    // @ts-expect-error mock assignment
+    Bun.spawn = makeMockSpawn(fixture, '', 0);
+
+    const result = await runSkillReview('skills/legibility-review/SKILL.md', 0);
+    expect(result.output).toContain('### Validation Checks');
+    // Summary reflects the failing run.
+    expect(result.output).toContain('Validation failed');
+    expect(result.output).toContain('1 error(s)');
+    // The failing "error" check is rendered with its message and marker.
+    expect(result.output).toContain('description field');
+    expect(result.output).toContain("'description' must not contain XML tags");
+    expect(result.output).toContain('❌');
+    // A passing check is also rendered.
+    expect(result.output).toContain('YAML frontmatter is valid');
+    expect(result.output).toContain('✅');
+  });
+
   test('CLI failure (non-zero exit)', async () => {
     // @ts-expect-error mock assignment
     Bun.spawn = makeMockSpawn('', 'Command not found', 1);

src/skill-review.ts

@@ -53,10 +53,49 @@ function formatEvaluation(value: unknown): string {
   return parts.length > 0 ? parts.join('\n') : JSON.stringify(value, null, 2);
 }
 
-/** Safely convert an unknown value to a readable string */
-function stringify(value: unknown): string {
-  if (typeof value === 'string') return value;
-  return JSON.stringify(value, null, 2);
+interface ValidationCheck {
+  name: string;
+  status: 'passed' | 'warning' | 'error';
+  message: string;
+}
+
+interface Validation {
+  checks?: ValidationCheck[];
+  overallPassed?: boolean;
+  errorCount?: number;
+  warningCount?: number;
+}
+
+/** Marker emoji for a validation check status */
+function statusMarker(status: ValidationCheck['status']): string {
+  if (status === 'passed') return '✅';
+  if (status === 'warning') return '⚠️';
+  return '❌';
+}
+
+/** Render validation checks into a readable markdown table with a summary line. */
+function formatValidation(validation: Validation): string {
+  const parts: string[] = [];
+
+  const passed = validation.overallPassed ? 'passed' : 'failed';
+  const errors = validation.errorCount ?? 0;
+  const warnings = validation.warningCount ?? 0;
+  parts.push(
+    `**Validation ${passed}** — ${errors} error(s), ${warnings} warning(s)`,
+  );
+
+  const checks = validation.checks ?? [];
+  if (checks.length > 0) {
+    parts.push('', '| | Check | Message |', '|--|-------|---------|');
+    for (const check of checks) {
+      const label = check.name.replace(/_/g, ' ');
+      parts.push(
+        `| ${statusMarker(check.status)} | **${label}** | ${check.message} |`,
+      );
+    }
+  }
+
+  return parts.join('\n');
 }
 
 /**
@@ -154,7 +193,7 @@ export async function runSkillReview(
   }
   let parsed: {
     contentJudge?: { normalizedScore?: number; evaluation?: unknown };
-    validation?: { output?: unknown };
+    validation?: Validation;
   };
 
   try {
@@ -174,9 +213,9 @@ export async function runSkillReview(
   const score = Math.round(normalizedScore * 100);
 
   const outputParts: string[] = [];
-  if (parsed.validation?.output) {
+  if (parsed.validation?.checks && parsed.validation.checks.length > 0) {
     outputParts.push(
-      '### Validation Checks\n\n' + stringify(parsed.validation.output),
+      '### Validation Checks\n\n' + formatValidation(parsed.validation),
     );
   }
   if (parsed.contentJudge?.evaluation) {