feat: add token optimization parameters (maxLength, selector, image resizing)

README.md

@@ -19,6 +19,10 @@ Chrome DevTools for reliable automation, in-depth debugging, and performance ana
 - **Reliable automation**. Uses
   [puppeteer](https://github.com/puppeteer/puppeteer) to automate actions in
   Chrome and automatically wait for action results.
+- **Token-efficient responses** (fork enhancement): Minimize token usage with
+  snapshot truncation (`maxLength`), CSS selector filtering (`selector`), and
+  image resizing (`maxWidth`/`maxHeight`). Inspired by
+  [fast-playwright-mcp](https://github.com/nicobailon/fast-playwright-mcp).
 
 ## Disclaimers
 
@@ -319,9 +323,55 @@ Check the performance of https://developers.chrome.com
 
 Your MCP client should open the browser and record a performance trace.
 
-> [!NOTE]  
+> [!NOTE]
 > The MCP server will start the browser automatically once the MCP client uses a tool that requires a running browser instance. Connecting to the Chrome DevTools MCP server on its own will not automatically start the browser.
 
+## Token Optimization (Fork Enhancement)
+
+This fork includes token optimization features inspired by [fast-playwright-mcp](https://github.com/nicobailon/fast-playwright-mcp).
+
+### Snapshot Optimization
+
+Use the following parameters with `take_snapshot` to reduce token usage:
+
+**Truncation** - Limit output to a maximum number of characters:
+
+```
+Take a snapshot with maxLength of 5000 characters
+```
+
+**CSS Selector Filtering** - Focus on a specific part of the page:
+
+```
+Take a snapshot with selector "#main-content"
+```
+
+The `selector` parameter limits the snapshot to only the subtree rooted at the matching element. This dramatically reduces output size when you only need to inspect a specific component.
+
+### Screenshot Optimization
+
+Use `maxWidth` and `maxHeight` with `take_screenshot` to resize images:
+
+```
+Take a screenshot with maxWidth 800 and maxHeight 600
+```
+
+Images are resized maintaining aspect ratio (using sharp library). This reduces the base64 payload size significantly, saving tokens when including screenshots in context.
+
+### Additional Parameters
+
+| Tool              | Parameter   | Description                                 |
+| ----------------- | ----------- | ------------------------------------------- |
+| `take_snapshot`   | `maxLength` | Maximum characters (truncates with notice)  |
+| `take_snapshot`   | `selector`  | CSS selector to limit scope                 |
+| `take_snapshot`   | `verbose`   | Include all a11y tree info (default: false) |
+| `take_screenshot` | `maxWidth`  | Maximum width in pixels                     |
+| `take_screenshot` | `maxHeight` | Maximum height in pixels                    |
+| `take_screenshot` | `quality`   | JPEG/WebP quality 0-100                     |
+| `take_screenshot` | `format`    | png, jpeg, or webp                          |
+
+See `src/expectation.ts` for the full expectation schema and tool defaults.
+
 ## Tools
 
 If you run into any issues, checkout our [troubleshooting guide](./docs/troubleshooting.md).

docs/tool-reference.md

@@ -340,6 +340,8 @@ so returned values have to JSON-serializable.
 - **filePath** (string) _(optional)_: The absolute path, or a path relative to the current working directory, to save the screenshot to instead of attaching it to the response.
 - **format** (enum: "png", "jpeg", "webp") _(optional)_: Type of format to save the screenshot as. Default is "png"
 - **fullPage** (boolean) _(optional)_: If set to true takes a screenshot of the full page instead of the currently visible viewport. Incompatible with uid.
+- **maxHeight** (number) _(optional)_: Maximum height in pixels. Image will be resized (maintaining aspect ratio) if larger. Useful for token efficiency.
+- **maxWidth** (number) _(optional)_: Maximum width in pixels. Image will be resized (maintaining aspect ratio) if larger. Useful for token efficiency.
 - **quality** (number) _(optional)_: Compression quality for JPEG and WebP formats (0-100). Higher values mean better quality but larger file sizes. Ignored for PNG format.
 - **uid** (string) _(optional)_: The uid of an element on the page from the page content snapshot. If omitted takes a pages screenshot.
 
@@ -354,6 +356,8 @@ in the DevTools Elements panel (if any).
 **Parameters:**
 
 - **filePath** (string) _(optional)_: The absolute path, or a path relative to the current working directory, to save the snapshot to instead of attaching it to the response.
+- **maxLength** (number) _(optional)_: Maximum characters for snapshot output. If exceeded, output is truncated with a notice. Useful for token efficiency.
+- **selector** (string) _(optional)_: CSS selector to limit snapshot scope. Only the subtree rooted at the matching element will be included. Useful for focusing on specific page sections.
 - **verbose** (boolean) _(optional)_: Whether to include all possible information available in the full a11y tree. Default is false.
 
 ---