chore(mcp): encourage relative path usage (#37857)

Author: pavelfeldman

packages/playwright/src/mcp/browser/config.ts

@@ -328,7 +328,7 @@ async function resolveFile(config: FullConfig, clientInfo: ClientInfo, fileName:
     fileName = fileName.split('\\').join('/');
     const resolvedFile = path.resolve(dir, fileName);
     if (!resolvedFile.startsWith(path.resolve(dir) + path.sep))
-      throw new Error(`Resolved file path for ${fileName} is outside of the output directory`);
+      throw new Error(`Resolved file path ${resolvedFile} is outside of the output directory ${dir}. Use relative file names to stay within the output directory.`);
     return resolvedFile;
   }
 

packages/playwright/src/mcp/browser/tools/pdf.ts

@@ -20,7 +20,7 @@ import * as javascript from '../codegen';
 import { dateAsFileName } from './utils';
 
 const pdfSchema = z.object({
-  filename: z.string().optional().describe('File name to save the pdf to. Defaults to `page-{timestamp}.pdf` if not specified.'),
+  filename: z.string().optional().describe('File name to save the pdf to. Defaults to `page-{timestamp}.pdf` if not specified. Prefer relative file names to stay within the output directory.'),
 });
 
 const pdf = defineTabTool({

packages/playwright/src/mcp/browser/tools/screenshot.ts

@@ -23,7 +23,7 @@ import type * as playwright from 'playwright-core';
 
 const screenshotSchema = z.object({
   type: z.enum(['png', 'jpeg']).default('png').describe('Image format for the screenshot. Default is png.'),
-  filename: z.string().optional().describe('File name to save the screenshot to. Defaults to `page-{timestamp}.{png|jpeg}` if not specified.'),
+  filename: z.string().optional().describe('File name to save the screenshot to. Defaults to `page-{timestamp}.{png|jpeg}` if not specified. Prefer relative file names to stay within the output directory.'),
   element: z.string().optional().describe('Human-readable element description used to obtain permission to screenshot the element. If not provided, the screenshot will be taken of viewport. If element is provided, ref must be provided too.'),
   ref: z.string().optional().describe('Exact target element reference from the page snapshot. If not provided, the screenshot will be taken of viewport. If ref is provided, element must be provided too.'),
   fullPage: z.boolean().optional().describe('When true, takes a screenshot of the full scrollable page, instead of the currently visible viewport. Cannot be used with element screenshots.'),