Add commands for listing and updating per-extension settings (#12664)

docs/extensions/index.md

@@ -163,11 +163,11 @@ The file has the following structure:
   your extension in the CLI. Note that we expect this name to match the
   extension directory name.
 - `version`: The version of the extension.
-- `mcpServers`: A map of MCP servers to configure. The key is the name of the
+- `mcpServers`: A map of MCP servers to settings. The key is the name of the
   server, and the value is the server configuration. These servers will be
-  loaded on startup just like MCP servers configured in a
+  loaded on startup just like MCP servers settingsd in a
   [`settings.json` file](../get-started/configuration.md). If both an extension
-  and a `settings.json` file configure an MCP server with the same name, the
+  and a `settings.json` file settings an MCP server with the same name, the
   server defined in the `settings.json` file takes precedence.
   - Note that all MCP server configuration options are supported except for
     `trust`.
@@ -223,6 +223,18 @@ When a user installs this extension, they will be prompted to enter their API
 key. The value will be saved to a `.env` file in the extension's directory
 (e.g., `<home>/.gemini/extensions/my-api-extension/.env`).
 
+You can view a list of an extension's settings by running:
+
+```
+gemini extensions settings list <extension name>
+```
+
+and you can update a given setting using:
+
+```
+gemini extensions settings set <extension name> <setting name>
+```
+
 ### Custom commands
 
 Extensions can provide [custom commands](../cli/custom-commands.md) by placing