Improve Copilot CLI installation doc (#1972)

* improve copilot cli installation doc

* revert custom config intro

* apply copilot suggestion

Author: kerobbi

docs/installation-guides/install-copilot-cli.md

@@ -1,10 +1,48 @@
 # Install GitHub MCP Server in Copilot CLI
 
-## Prerequisites
+The GitHub MCP server comes pre-installed in Copilot CLI, with read-only tools enabled by default.
 
-1. Copilot CLI installed (see [official Copilot CLI documentation](https://docs.github.com/en/copilot/concepts/agents/about-copilot-cli))
-2. [GitHub Personal Access Token](https://github.com/settings/personal-access-tokens/new) with appropriate scopes
-3. For local installation: [Docker](https://www.docker.com/) installed and running
+## Built-in Server
+
+To verify the server is available, from an active Copilot CLI session:
+
+```bash
+/mcp show github-mcp-server
+```
+
+### Per-Session Customization
+
+Use CLI flags to customize the server for a session:
+
+```bash
+# Enable an additional toolset
+copilot --add-github-mcp-toolset discussions
+
+# Enable multiple additional toolsets
+copilot --add-github-mcp-toolset discussions --add-github-mcp-toolset stargazers
+
+# Enable all toolsets
+copilot --enable-all-github-mcp-tools
+
+# Enable a specific tool
+copilot --add-github-mcp-tool list_discussions
+
+# Disable the built-in server entirely
+copilot --disable-builtin-mcps
+```
+
+Run `copilot --help` for all available flags. For the list of toolsets, see [Available toolsets](../../README.md#available-toolsets); for the list of tools, see [Tools](../../README.md#tools).
+
+## Custom Configuration
+
+You can configure the GitHub MCP server in Copilot CLI using either the interactive command or by manually editing the configuration file.
+
+> **Server naming:** Name your server `github-mcp-server` to replace the built-in server, or use a different name (e.g., `github`) to run alongside it.
+
+### Prerequisites
+
+1. [GitHub Personal Access Token](https://github.com/settings/personal-access-tokens/new) with appropriate scopes
+2. For local server: [Docker](https://www.docker.com/) installed and running
 
 <details>
 <summary><b>Storing Your PAT Securely</b></summary>
@@ -19,21 +57,17 @@ export GITHUB_PERSONAL_ACCESS_TOKEN=your_token_here
 
 </details>
 
-## GitHub MCP Server Configuration
-
-You can configure the GitHub MCP server in Copilot CLI using either the interactive command or by manually editing the configuration file.
-
 ### Method 1: Interactive Setup (Recommended)
 
-Use the Copilot CLI to interactively add the MCP server:
+From an active Copilot CLI session, run the interactive command:
 
 ```bash
 /mcp add
 ```
 
-Follow the prompts to configure the GitHub MCP server.
+Follow the prompts to configure the server.
 
-### Method 2: Manual Configuration
+### Method 2: Manual Setup
 
 Create or edit the configuration file `~/.copilot/mcp-config.json` and add one of the following configurations:
 
@@ -45,6 +79,7 @@ Connect to the hosted MCP server:
 {
   "mcpServers": {
     "github": {
+      "type": "http",
       "url": "https://api.githubcopilot.com/mcp/",
       "headers": {
         "Authorization": "Bearer ${GITHUB_PERSONAL_ACCESS_TOKEN}"
@@ -54,6 +89,8 @@ Connect to the hosted MCP server:
 }
 ```
 
+For additional options like toolsets and read-only mode, see the [remote server documentation](../remote-server.md#optional-headers).
+
 #### Local Docker
 
 With Docker running, you can run the GitHub MCP server in a container:
@@ -81,9 +118,13 @@ With Docker running, you can run the GitHub MCP server in a container:
 
 #### Binary
 
-You can download the latest binary release from the [GitHub releases page](https://github.com/github/github-mcp-server/releases) or build it from source by running `go build -o github-mcp-server ./cmd/github-mcp-server`.
+You can download the latest binary release from the [GitHub releases page](https://github.com/github/github-mcp-server/releases) or build it from source by running:
 
-Then, replacing `/path/to/binary` with the actual path to your binary, configure Copilot CLI with:
+```bash
+go build -o github-mcp-server ./cmd/github-mcp-server
+```
+
+Then configure (replace `/path/to/binary` with the actual path):
 
 ```json
 {
@@ -101,35 +142,30 @@ Then, replacing `/path/to/binary` with the actual path to your binary, configure
 
 ## Verification
 
-To verify that the GitHub MCP server has been configured:
-
-1. Start or restart Copilot CLI
-2. The GitHub tools should be available for use in your conversations
+1. Restart Copilot CLI
+2. Run `/mcp show` to list configured servers
+3. Try: "List my GitHub repositories"
 
 ## Troubleshooting
 
 ### Local Server Issues
 
 - **Docker errors**: Ensure Docker Desktop is running
-    ```bash
-    docker --version
-    ```
 - **Image pull failures**: Try `docker logout ghcr.io` then retry
-- **Docker not found**: Install Docker Desktop and ensure it's running
 
 ### Authentication Issues
 
 - **Invalid PAT**: Verify your GitHub PAT has correct scopes:
-    - `repo` - Repository operations
-    - `read:packages` - Docker image access (if using Docker)
+  - `repo` - Repository operations
+  - `read:packages` - Docker image access (if using Docker)
 - **Token expired**: Generate a new GitHub PAT
 
 ### Configuration Issues
 
 - **Invalid JSON**: Validate your configuration:
-    ```bash
-    cat ~/.copilot/mcp-config.json | jq .
-    ```
+  ```bash
+  cat ~/.copilot/mcp-config.json | jq .
+  ```
 
 ## References