diff --git a/scripts/openclaw-performance-source-summary.mjs b/scripts/openclaw-performance-source-summary.mjs
index 3f8465d6c109..31f092def46f 100644
--- a/scripts/openclaw-performance-source-summary.mjs
+++ b/scripts/openclaw-performance-source-summary.mjs
@@ -255,6 +255,12 @@ function validateExtensionMemoryArtifact(extensionMemory, filePath) {
   if (!Array.isArray(extensionMemory?.topByDeltaMb) || extensionMemory.topByDeltaMb.length === 0) {
     throw new Error(`[source-performance] missing extension memory rows: ${filePath}`);
   }
+  if (
+    !finiteNumber(extensionMemory?.baseline?.maxRssMb) ||
+    !finiteNumber(extensionMemory?.combined?.maxRssMb)
+  ) {
+    throw new Error(`[source-performance] incomplete extension memory context: ${filePath}`);
+  }
   for (const entry of extensionMemory.topByDeltaMb) {
     if (!finiteNumber(entry?.maxRssMb) || !finiteNumber(entry?.deltaFromBaselineMb)) {
       throw new Error(
@@ -510,6 +516,30 @@ function buildExtensionMemoryRows(extensionMemory) {
     ]);
 }
 
+function buildExtensionMemoryContextRows(extensionMemory) {
+  const baselineMb = extensionMemory?.baseline?.maxRssMb;
+  const combinedMb = extensionMemory?.combined?.maxRssMb;
+  const totalEntries = extensionMemory?.counts?.totalEntries;
+  return [
+    [
+      "empty Node process",
+      formatMb(baselineMb),
+      formatMb(0),
+      extensionMemory?.baseline?.status ?? "unknown",
+    ],
+    [
+      finiteNumber(totalEntries)
+        ? `all ${totalEntries} bundled plugins`
+        : "all selected bundled plugins",
+      formatMb(combinedMb),
+      finiteNumber(baselineMb) && finiteNumber(combinedMb)
+        ? formatMb(combinedMb - baselineMb)
+        : "n/a",
+      extensionMemory?.combined?.status ?? "unknown",
+    ],
+  ];
+}
+
 function buildSqlitePerfRows(sqlitePerf) {
   if (!sqlitePerf) {
     return [];
@@ -606,8 +636,14 @@ export function buildMarkdown(sourceDir, baselineSourceDir) {
     ),
     "## Bundled Plugin Import Memory",
     "",
+    "Per-plugin rows are isolated cold imports and are not additive. The combined row measures all selected bundled-plugin entrypoints in one process.",
+    "",
     ...table(
-      ["plugin", "max RSS", "delta from empty process", "status"],
+      ["measurement", "max RSS", "delta from empty process", "status"],
+      buildExtensionMemoryContextRows(current.extensionMemory),
+    ),
+    ...table(
+      ["plugin", "isolated max RSS", "isolated delta from empty process", "status"],
       buildExtensionMemoryRows(current.extensionMemory),
     ),
     "## Startup Hotspots",
diff --git a/test/scripts/openclaw-performance-source-summary.test.ts b/test/scripts/openclaw-performance-source-summary.test.ts
index 667bc96608a2..0f012bda0910 100644
--- a/test/scripts/openclaw-performance-source-summary.test.ts
+++ b/test/scripts/openclaw-performance-source-summary.test.ts
@@ -73,6 +73,9 @@ function writeSourceFixture(sourceDir: string) {
     },
   });
   writeJson(path.join(sourceDir, "extension-memory.json"), {
+    baseline: { maxRssMb: 50, status: "ok" },
+    combined: { maxRssMb: 180, status: "ok" },
+    counts: { totalEntries: 12 },
     topByDeltaMb: [
       { dir: "extensions/browser", maxRssMb: 80, deltaFromBaselineMb: 12, status: "ok" },
     ],
@@ -171,6 +174,13 @@ describe("buildMarkdown", () => {
     expect(buildMarkdown(sourceDir, null)).not.toContain("phase.load.total");
     expect(buildMarkdown(sourceDir, null)).not.toContain("phase.load.itemCount");
     expect(buildMarkdown(sourceDir, null)).not.toContain("memory.ready.heapUsedMb");
+    expect(buildMarkdown(sourceDir, null)).toContain(
+      "Per-plugin rows are isolated cold imports and are not additive.",
+    );
+    expect(buildMarkdown(sourceDir, null)).toContain(
+      "| all 12 bundled plugins | 180.0MB | 130.0MB | ok |",
+    );
+    expect(buildMarkdown(sourceDir, null)).toContain("isolated delta from empty process");
   });
 
   it("rejects a missing source directory", () => {
@@ -230,6 +240,20 @@ describe("buildMarkdown", () => {
     );
   });
 
+  it("rejects extension memory artifacts without combined-process context", () => {
+    const sourceDir = mkTmpRoot();
+    writeSourceFixture(sourceDir);
+    writeJson(path.join(sourceDir, "extension-memory.json"), {
+      topByDeltaMb: [
+        { dir: "extensions/browser", maxRssMb: 80, deltaFromBaselineMb: 12, status: "ok" },
+      ],
+    });
+
+    expect(() => buildMarkdown(sourceDir, null)).toThrow(
+      "[source-performance] incomplete extension memory context:",
+    );
+  });
+
   it("allows source performance fixtures without older-ref SQLite smoke artifacts", () => {
     const sourceDir = mkTmpRoot();
     writeSourceFixture(sourceDir);