diff --git a/dist/index.js b/dist/index.js
index ff1922f..952c1c8 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -57733,16 +57733,48 @@ function generateMarkdownReport(report) {
     lines.push(`| Branch Total Time | ${formatTime(report.totalBranchTime)} |`);
     lines.push(`| Base Total Time | ${formatTime(report.totalBaseTime)} |`);
     lines.push("");
-    // Overall status
+    // Overall status with passing and failing configurations
     if (report.diffCount === 0) {
         lines.push("## ✅ No API Changes");
         lines.push("");
-        lines.push("No differences detected between the current branch and the comparison ref.");
+        lines.push("All configurations passed with no differences detected.");
+        lines.push("");
+        lines.push("**✅ Passing configurations (no changes detected):**");
+        for (const result of report.results) {
+            if (!result.error && !result.diffs.has("error") && !result.hasDifferences) {
+                lines.push(`- ${result.configName}`);
+            }
+        }
     }
     else {
         lines.push("## 📋 API Changes Detected");
         lines.push("");
-        lines.push(`${report.diffCount} configuration(s) have changes. Review below to ensure they are intentional.`);
+        // List passing configurations first
+        const passingConfigs = report.results.filter((r) => !r.error && !r.diffs.has("error") && !r.hasDifferences);
+        if (passingConfigs.length > 0) {
+            lines.push("**✅ Passing configurations (no changes detected):**");
+            for (const result of passingConfigs) {
+                lines.push(`- ${result.configName}`);
+            }
+            lines.push("");
+        }
+        // List configurations with changes (excluding errors)
+        const changedConfigs = report.results.filter((r) => r.hasDifferences && !r.error && !r.diffs.has("error"));
+        if (changedConfigs.length > 0) {
+            lines.push("**⚠️ Configurations with changes:**");
+            for (const result of changedConfigs) {
+                lines.push(`- ${result.configName} (see diff below)`);
+            }
+            lines.push("");
+        }
+        // List configurations with errors if any
+        const errorConfigs = report.results.filter((r) => r.error || r.diffs.has("error"));
+        if (errorConfigs.length > 0) {
+            lines.push("**❌ Configurations with errors:**");
+            for (const result of errorConfigs) {
+                lines.push(`- ${result.configName}`);
+            }
+        }
     }
     lines.push("");
     // Per-configuration results
@@ -57851,18 +57883,44 @@ function generatePRSummary(report) {
         lines.push("## ✅ MCP Conformance: No Changes");
         lines.push("");
         lines.push(`Tested ${report.results.length} configuration(s) - no API changes detected.`);
+        lines.push("");
+        lines.push("**✅ Passing configurations:**");
+        for (const result of report.results.filter((r) => !r.error && !r.diffs.has("error") && !r.hasDifferences)) {
+            lines.push(`- ${result.configName}`);
+        }
     }
     else {
         lines.push("## 📋 MCP Conformance: API Changes Detected");
         lines.push("");
         lines.push(`**${report.diffCount}** of ${report.results.length} configuration(s) have changes.`);
         lines.push("");
-        lines.push("### Changed Endpoints");
-        lines.push("");
-        for (const result of report.results.filter((r) => r.hasDifferences)) {
-            lines.push(`- **${result.configName}:** ${Array.from(result.diffs.keys()).join(", ")}`);
+        // List passing configurations
+        const passingConfigs = report.results.filter((r) => !r.error && !r.diffs.has("error") && !r.hasDifferences);
+        if (passingConfigs.length > 0) {
+            lines.push("**✅ Passing configurations (no changes):**");
+            for (const result of passingConfigs) {
+                lines.push(`- ${result.configName}`);
+            }
+            lines.push("");
+        }
+        // List configurations with changes (excluding errors)
+        const changedConfigs = report.results.filter((r) => r.hasDifferences && !r.error && !r.diffs.has("error"));
+        if (changedConfigs.length > 0) {
+            lines.push("**⚠️ Changed configurations:**");
+            for (const result of changedConfigs) {
+                lines.push(`- **${result.configName}:** ${Array.from(result.diffs.keys()).join(", ")}`);
+            }
+            lines.push("");
+        }
+        // List configurations with errors if any
+        const errorConfigs = report.results.filter((r) => r.error || r.diffs.has("error"));
+        if (errorConfigs.length > 0) {
+            lines.push("**❌ Configurations with errors:**");
+            for (const result of errorConfigs) {
+                lines.push(`- ${result.configName}`);
+            }
+            lines.push("");
         }
-        lines.push("");
         lines.push("See the full report in the job summary for details.");
     }
     return lines.join("\n");
diff --git a/src/__tests__/reporter.test.ts b/src/__tests__/reporter.test.ts
new file mode 100644
index 0000000..0143839
--- /dev/null
+++ b/src/__tests__/reporter.test.ts
@@ -0,0 +1,400 @@
+/**
+ * Tests for report generation
+ */
+
+import { generateReport, generateMarkdownReport, generatePRSummary } from "../reporter.js";
+import type { TestResult, ConformanceReport } from "../types.js";
+
+describe("generateReport", () => {
+  it("calculates passed and diff counts correctly", () => {
+    const results: TestResult[] = [
+      {
+        configName: "config1",
+        transport: "stdio",
+        branchTime: 100,
+        baseTime: 90,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+      {
+        configName: "config2",
+        transport: "stdio",
+        branchTime: 120,
+        baseTime: 110,
+        hasDifferences: true,
+        diffs: new Map([["tools", "diff content"]]),
+      },
+      {
+        configName: "config3",
+        transport: "streamable-http",
+        branchTime: 80,
+        baseTime: 85,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+    ];
+
+    const report = generateReport(results, "main", "v1.0.0");
+
+    expect(report.passedCount).toBe(2);
+    expect(report.diffCount).toBe(1);
+    expect(report.results.length).toBe(3);
+    expect(report.totalBranchTime).toBe(300);
+    expect(report.totalBaseTime).toBe(285);
+  });
+});
+
+describe("generateMarkdownReport", () => {
+  it("lists all passing configurations when no diffs", () => {
+    const results: TestResult[] = [
+      {
+        configName: "config1",
+        transport: "stdio",
+        branchTime: 100,
+        baseTime: 90,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+      {
+        configName: "config2",
+        transport: "streamable-http",
+        branchTime: 120,
+        baseTime: 110,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+    ];
+
+    const report: ConformanceReport = {
+      generatedAt: "2024-01-01T00:00:00.000Z",
+      currentBranch: "main",
+      compareRef: "v1.0.0",
+      results,
+      totalBranchTime: 220,
+      totalBaseTime: 200,
+      passedCount: 2,
+      diffCount: 0,
+    };
+
+    const markdown = generateMarkdownReport(report);
+
+    expect(markdown).toContain("## ✅ No API Changes");
+    expect(markdown).toContain("All configurations passed with no differences detected");
+    expect(markdown).toContain("**✅ Passing configurations (no changes detected):**");
+    expect(markdown).toContain("- config1");
+    expect(markdown).toContain("- config2");
+  });
+
+  it("separates passing and failing configurations when there are diffs", () => {
+    const results: TestResult[] = [
+      {
+        configName: "default",
+        transport: "stdio",
+        branchTime: 100,
+        baseTime: 90,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+      {
+        configName: "read-only",
+        transport: "stdio",
+        branchTime: 95,
+        baseTime: 88,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+      {
+        configName: "toolsets-all",
+        transport: "stdio",
+        branchTime: 120,
+        baseTime: 110,
+        hasDifferences: true,
+        diffs: new Map([["tools", "diff content"]]),
+      },
+      {
+        configName: "http-server",
+        transport: "streamable-http",
+        branchTime: 130,
+        baseTime: 125,
+        hasDifferences: true,
+        diffs: new Map([
+          ["initialize", "server version changed"],
+          ["resources", "new resource added"],
+        ]),
+      },
+    ];
+
+    const report: ConformanceReport = {
+      generatedAt: "2024-01-01T00:00:00.000Z",
+      currentBranch: "main",
+      compareRef: "v1.0.0",
+      results,
+      totalBranchTime: 445,
+      totalBaseTime: 413,
+      passedCount: 2,
+      diffCount: 2,
+    };
+
+    const markdown = generateMarkdownReport(report);
+
+    expect(markdown).toContain("## 📋 API Changes Detected");
+    expect(markdown).toContain("**✅ Passing configurations (no changes detected):**");
+    expect(markdown).toContain("- default");
+    expect(markdown).toContain("- read-only");
+    expect(markdown).toContain("**⚠️ Configurations with changes:**");
+    expect(markdown).toContain("- toolsets-all (see diff below)");
+    expect(markdown).toContain("- http-server (see diff below)");
+  });
+
+  it("shows error configurations separately", () => {
+    const results: TestResult[] = [
+      {
+        configName: "passing-config",
+        transport: "stdio",
+        branchTime: 100,
+        baseTime: 90,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+      {
+        configName: "error-config",
+        transport: "stdio",
+        branchTime: 0,
+        baseTime: 0,
+        hasDifferences: true,
+        diffs: new Map([["error", "Failed to start server"]]),
+      },
+    ];
+
+    const report: ConformanceReport = {
+      generatedAt: "2024-01-01T00:00:00.000Z",
+      currentBranch: "main",
+      compareRef: "v1.0.0",
+      results,
+      totalBranchTime: 100,
+      totalBaseTime: 90,
+      passedCount: 1,
+      diffCount: 1,
+    };
+
+    const markdown = generateMarkdownReport(report);
+
+    expect(markdown).toContain("**✅ Passing configurations (no changes detected):**");
+    expect(markdown).toContain("- passing-config");
+    expect(markdown).toContain("**❌ Configurations with errors:**");
+    expect(markdown).toContain("- error-config");
+    // Error configs should not be in the changes section
+    expect(markdown).not.toContain("error-config (see diff below)");
+  });
+
+  it("does not show empty sections", () => {
+    const results: TestResult[] = [
+      {
+        configName: "config-with-diff",
+        transport: "stdio",
+        branchTime: 120,
+        baseTime: 110,
+        hasDifferences: true,
+        diffs: new Map([["tools", "diff content"]]),
+      },
+    ];
+
+    const report: ConformanceReport = {
+      generatedAt: "2024-01-01T00:00:00.000Z",
+      currentBranch: "main",
+      compareRef: "v1.0.0",
+      results,
+      totalBranchTime: 120,
+      totalBaseTime: 110,
+      passedCount: 0,
+      diffCount: 1,
+    };
+
+    const markdown = generateMarkdownReport(report);
+
+    // Should not show passing configurations section when there are none
+    expect(markdown).not.toContain("**✅ Passing configurations (no changes detected):**");
+    expect(markdown).toContain("**⚠️ Configurations with changes:**");
+    expect(markdown).toContain("- config-with-diff (see diff below)");
+  });
+});
+
+describe("generatePRSummary", () => {
+  it("lists passing configurations when no diffs", () => {
+    const results: TestResult[] = [
+      {
+        configName: "config1",
+        transport: "stdio",
+        branchTime: 100,
+        baseTime: 90,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+      {
+        configName: "config2",
+        transport: "stdio",
+        branchTime: 120,
+        baseTime: 110,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+    ];
+
+    const report: ConformanceReport = {
+      generatedAt: "2024-01-01T00:00:00.000Z",
+      currentBranch: "main",
+      compareRef: "v1.0.0",
+      results,
+      totalBranchTime: 220,
+      totalBaseTime: 200,
+      passedCount: 2,
+      diffCount: 0,
+    };
+
+    const summary = generatePRSummary(report);
+
+    expect(summary).toContain("## ✅ MCP Conformance: No Changes");
+    expect(summary).toContain("Tested 2 configuration(s) - no API changes detected");
+    expect(summary).toContain("**✅ Passing configurations:**");
+    expect(summary).toContain("- config1");
+    expect(summary).toContain("- config2");
+  });
+
+  it("shows both passing and changed configurations when there are diffs", () => {
+    const results: TestResult[] = [
+      {
+        configName: "default",
+        transport: "stdio",
+        branchTime: 100,
+        baseTime: 90,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+      {
+        configName: "read-only",
+        transport: "stdio",
+        branchTime: 95,
+        baseTime: 88,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+      {
+        configName: "toolsets-all",
+        transport: "stdio",
+        branchTime: 120,
+        baseTime: 110,
+        hasDifferences: true,
+        diffs: new Map([["tools", "diff content"]]),
+      },
+    ];
+
+    const report: ConformanceReport = {
+      generatedAt: "2024-01-01T00:00:00.000Z",
+      currentBranch: "main",
+      compareRef: "v1.0.0",
+      results,
+      totalBranchTime: 315,
+      totalBaseTime: 288,
+      passedCount: 2,
+      diffCount: 1,
+    };
+
+    const summary = generatePRSummary(report);
+
+    expect(summary).toContain("## 📋 MCP Conformance: API Changes Detected");
+    expect(summary).toContain("**1** of 3 configuration(s) have changes");
+    expect(summary).toContain("**✅ Passing configurations (no changes):**");
+    expect(summary).toContain("- default");
+    expect(summary).toContain("- read-only");
+    expect(summary).toContain("**⚠️ Changed configurations:**");
+    expect(summary).toContain("- **toolsets-all:** tools");
+  });
+
+  it("does not show passing section when all configs have diffs", () => {
+    const results: TestResult[] = [
+      {
+        configName: "config1",
+        transport: "stdio",
+        branchTime: 100,
+        baseTime: 90,
+        hasDifferences: true,
+        diffs: new Map([["tools", "diff content"]]),
+      },
+      {
+        configName: "config2",
+        transport: "stdio",
+        branchTime: 120,
+        baseTime: 110,
+        hasDifferences: true,
+        diffs: new Map([["initialize", "version changed"]]),
+      },
+    ];
+
+    const report: ConformanceReport = {
+      generatedAt: "2024-01-01T00:00:00.000Z",
+      currentBranch: "main",
+      compareRef: "v1.0.0",
+      results,
+      totalBranchTime: 220,
+      totalBaseTime: 200,
+      passedCount: 0,
+      diffCount: 2,
+    };
+
+    const summary = generatePRSummary(report);
+
+    expect(summary).not.toContain("**✅ Passing configurations");
+    expect(summary).toContain("**⚠️ Changed configurations:**");
+  });
+
+  it("shows error configurations separately in PR summary", () => {
+    const results: TestResult[] = [
+      {
+        configName: "passing-config",
+        transport: "stdio",
+        branchTime: 100,
+        baseTime: 90,
+        hasDifferences: false,
+        diffs: new Map(),
+      },
+      {
+        configName: "changed-config",
+        transport: "stdio",
+        branchTime: 120,
+        baseTime: 110,
+        hasDifferences: true,
+        diffs: new Map([["tools", "diff content"]]),
+      },
+      {
+        configName: "error-config",
+        transport: "stdio",
+        branchTime: 0,
+        baseTime: 0,
+        hasDifferences: true,
+        diffs: new Map([["error", "Failed to start server"]]),
+      },
+    ];
+
+    const report: ConformanceReport = {
+      generatedAt: "2024-01-01T00:00:00.000Z",
+      currentBranch: "main",
+      compareRef: "v1.0.0",
+      results,
+      totalBranchTime: 220,
+      totalBaseTime: 200,
+      passedCount: 1,
+      diffCount: 2,
+    };
+
+    const summary = generatePRSummary(report);
+
+    expect(summary).toContain("**✅ Passing configurations (no changes):**");
+    expect(summary).toContain("- passing-config");
+    expect(summary).toContain("**⚠️ Changed configurations:**");
+    expect(summary).toContain("- **changed-config:** tools");
+    expect(summary).toContain("**❌ Configurations with errors:**");
+    expect(summary).toContain("- error-config");
+    // Error configs should not be in the changed section
+    expect(summary).not.toContain("**error-config:**");
+  });
+});
diff --git a/src/reporter.ts b/src/reporter.ts
index 9e11b82..39709ed 100644
--- a/src/reporter.ts
+++ b/src/reporter.ts
@@ -57,17 +57,54 @@ export function generateMarkdownReport(report: ConformanceReport): string {
   lines.push(`| Base Total Time | ${formatTime(report.totalBaseTime)} |`);
   lines.push("");
 
-  // Overall status
+  // Overall status with passing and failing configurations
   if (report.diffCount === 0) {
     lines.push("## ✅ No API Changes");
     lines.push("");
-    lines.push("No differences detected between the current branch and the comparison ref.");
+    lines.push("All configurations passed with no differences detected.");
+    lines.push("");
+    lines.push("**✅ Passing configurations (no changes detected):**");
+    for (const result of report.results) {
+      if (!result.error && !result.diffs.has("error") && !result.hasDifferences) {
+        lines.push(`- ${result.configName}`);
+      }
+    }
   } else {
     lines.push("## 📋 API Changes Detected");
     lines.push("");
-    lines.push(
-      `${report.diffCount} configuration(s) have changes. Review below to ensure they are intentional.`
+
+    // List passing configurations first
+    const passingConfigs = report.results.filter(
+      (r) => !r.error && !r.diffs.has("error") && !r.hasDifferences
+    );
+    if (passingConfigs.length > 0) {
+      lines.push("**✅ Passing configurations (no changes detected):**");
+      for (const result of passingConfigs) {
+        lines.push(`- ${result.configName}`);
+      }
+      lines.push("");
+    }
+
+    // List configurations with changes (excluding errors)
+    const changedConfigs = report.results.filter(
+      (r) => r.hasDifferences && !r.error && !r.diffs.has("error")
     );
+    if (changedConfigs.length > 0) {
+      lines.push("**⚠️ Configurations with changes:**");
+      for (const result of changedConfigs) {
+        lines.push(`- ${result.configName} (see diff below)`);
+      }
+      lines.push("");
+    }
+
+    // List configurations with errors if any
+    const errorConfigs = report.results.filter((r) => r.error || r.diffs.has("error"));
+    if (errorConfigs.length > 0) {
+      lines.push("**❌ Configurations with errors:**");
+      for (const result of errorConfigs) {
+        lines.push(`- ${result.configName}`);
+      }
+    }
   }
   lines.push("");
 
@@ -194,6 +231,13 @@ export function generatePRSummary(report: ConformanceReport): string {
     lines.push("## ✅ MCP Conformance: No Changes");
     lines.push("");
     lines.push(`Tested ${report.results.length} configuration(s) - no API changes detected.`);
+    lines.push("");
+    lines.push("**✅ Passing configurations:**");
+    for (const result of report.results.filter(
+      (r) => !r.error && !r.diffs.has("error") && !r.hasDifferences
+    )) {
+      lines.push(`- ${result.configName}`);
+    }
   } else {
     lines.push("## 📋 MCP Conformance: API Changes Detected");
     lines.push("");
@@ -201,14 +245,41 @@ export function generatePRSummary(report: ConformanceReport): string {
       `**${report.diffCount}** of ${report.results.length} configuration(s) have changes.`
     );
     lines.push("");
-    lines.push("### Changed Endpoints");
-    lines.push("");
 
-    for (const result of report.results.filter((r) => r.hasDifferences)) {
-      lines.push(`- **${result.configName}:** ${Array.from(result.diffs.keys()).join(", ")}`);
+    // List passing configurations
+    const passingConfigs = report.results.filter(
+      (r) => !r.error && !r.diffs.has("error") && !r.hasDifferences
+    );
+    if (passingConfigs.length > 0) {
+      lines.push("**✅ Passing configurations (no changes):**");
+      for (const result of passingConfigs) {
+        lines.push(`- ${result.configName}`);
+      }
+      lines.push("");
+    }
+
+    // List configurations with changes (excluding errors)
+    const changedConfigs = report.results.filter(
+      (r) => r.hasDifferences && !r.error && !r.diffs.has("error")
+    );
+    if (changedConfigs.length > 0) {
+      lines.push("**⚠️ Changed configurations:**");
+      for (const result of changedConfigs) {
+        lines.push(`- **${result.configName}:** ${Array.from(result.diffs.keys()).join(", ")}`);
+      }
+      lines.push("");
+    }
+
+    // List configurations with errors if any
+    const errorConfigs = report.results.filter((r) => r.error || r.diffs.has("error"));
+    if (errorConfigs.length > 0) {
+      lines.push("**❌ Configurations with errors:**");
+      for (const result of errorConfigs) {
+        lines.push(`- ${result.configName}`);
+      }
+      lines.push("");
     }
 
-    lines.push("");
     lines.push("See the full report in the job summary for details.");
   }