diff --git a/packages/playwright-core/src/tools/mcp/config.ts b/packages/playwright-core/src/tools/mcp/config.ts
index 0fa8802d2be5a..8d141d9037098 100644
--- a/packages/playwright-core/src/tools/mcp/config.ts
+++ b/packages/playwright-core/src/tools/mcp/config.ts
@@ -225,10 +225,12 @@ async function validateBrowserConfig(browser: MergedConfig['browser']): Promise<
   }
 
   if (browserName === 'chromium' && browser.launchOptions.chromiumSandbox === undefined) {
-    if (process.platform === 'linux')
-      browser.launchOptions.chromiumSandbox = browser.launchOptions.channel !== 'chromium' && browser.launchOptions.channel !== 'chrome-for-testing';
-    else
+    if (process.platform === 'linux') {
+      const channel = browser.launchOptions.channel;
+      browser.launchOptions.chromiumSandbox = channel !== undefined && channel !== 'chromium' && channel !== 'chrome-for-testing';
+    } else {
       browser.launchOptions.chromiumSandbox = true;
+    }
   }
 
   if (browser.isolated && browser.userDataDir)
diff --git a/packages/playwright-core/src/tools/skills/playwright-cli/SKILL.md b/packages/playwright-core/src/tools/skills/playwright-cli/SKILL.md
index b7c883842d260..632fc93e7b946 100644
--- a/packages/playwright-core/src/tools/skills/playwright-cli/SKILL.md
+++ b/packages/playwright-core/src/tools/skills/playwright-cli/SKILL.md
@@ -359,6 +359,16 @@ When local version is available, use `npx playwright cli` in all commands. Other
 npm install -g @playwright/cli@latest
 ```
 
+To install or update the agent skill itself, run:
+
+```bash
+# Install globally for all agents:
+playwright-cli install --skills=agents --global
+
+# Install only for Claude Desktop:
+playwright-cli install --skills=claude
+```
+
 ## Example: Form submission
 
 ```bash