docs: document admin toggle for MCP content writes

references/integrations/lightdash-mcp.mdx

@@ -377,6 +377,10 @@ MCP can read, create, and edit Lightdash charts and dashboards using the same [c
 
 These tools reuse the same permissions, validation, and project context as the [Lightdash CLI](/guides/cli/how-to-install-the-lightdash-cli) `download` and `upload` commands, so the user driving the MCP session needs the same access required to manage that content in Lightdash.
 
+<Info>
+  **Admin kill-switch.** Organization admins can disable content writes across all MCP clients from **Settings → Ask AI → General** by turning off **Allow content changes via MCP**. When this is off, `create_content` and `edit_content` are not registered for any MCP client in the organization — reading content over MCP is unaffected, and per-user permissions still apply when it's on. The toggle is **on by default**.
+</Info>
+
 <Info>
   When prompting an agent to build content, ask it to use [verified content](#data-exploration) as a reference. The agent can call `find_content` and `read_content` on a verified chart, then use that JSON as the template for `create_content` — giving you new content that follows the patterns your team has already approved.
 </Info>