clarify readme

Author: ashwin-ant

README.md

@@ -2,12 +2,44 @@
 
 The MCP inspector is a developer tool for testing and debugging MCP servers.
 
-It can be run easily from `npx`:
+![MCP Inspector Screenshot](mcp-inspector.png)
+
+## Running the Inspector
+
+### From an MCP server repository
+
+To inspect an MCP server implementation, there's no need to clone this repo. Instead, use `npx`. For example, if your server is built at `build/index.js`:
+
+```bash
+npx @modelcontextprotocol/inspector build/index.js
+```
+
+You can also pass arguments along which will get passed as arguments to your MCP server:
 
 ```
-npx @modelcontextprotocol/inspector
+npx @modelcontextprotocol/inspector build/index.js arg1 arg2 ...
+```
+
+The inspector runs both a client UI and an MCP proxy server:
+- Client UI: http://localhost:5173 (configurable via `CLIENT_PORT`) - open this in your browser
+- Proxy Server: http://localhost:3000 (configurable via `SERVER_PORT`) - used internally, no need to access directly
+
+### From this repository
+
+If you're working on the inspector itself:
+
+Development mode:
+
+```bash
+npm run dev
+```
+
+Production mode:
+
+```bash
+npm run build
+npm start
 ```
-This starts a localhost web server on port 5173. You can then visit  http://localhost:5173/ to interact with the tool.
 
 ## License