diff --git a/README.md b/README.md
index 70c2e50..54985a2 100644
--- a/README.md
+++ b/README.md
@@ -74,6 +74,7 @@ The input is [the existing neovim-dots repository](https://git.cyber.ayyalasomay
 
 Home Manager deploys its files under `~/.config/nvim`, with the **Lua, AstroNvim, Lazy, Mason, plugins and keymaps unchanged**. `programs.neovim.configure` stays empty so Neovim discovers `init.lua` normally. No Nixvim or custom Lua loader.
 
+- `tools.nix` supplies GCC/Make, pkg-config, Python, Node, Lua 5.1/LuaRocks and `nix-ld` for the existing plugin builds and Mason's upstream Linux executables. These are runtime prerequisites, not a replacement plugin manager or project-template framework.
 - Configuration files are linked from the pinned source and managed by Nix. Change the upstream repo and its input revision rather than editing generated links.
 - Lazy's `lazy-lock.json` must remain writable. The config seeds a copy at `~/.local/state/nvim/locks/<dotfile-revision>.json` and links to it. A new dotfile revision gets its own original lock; repeated activation preserves runtime changes to an existing lock.
 - A declared migration preserves the earlier manual checkout intact at `~/projects/neovim-dots-before-nix`. It refuses to overwrite an existing backup. On a clean home this migration does nothing.
diff --git a/tools.nix b/tools.nix
index 04f5d3b..71c331b 100644
--- a/tools.nix
+++ b/tools.nix
@@ -6,10 +6,20 @@ in
 {
   programs.git.enable = true;
   programs.zsh.enable = true;
+  # Mason's upstream Linux executables expect a conventional dynamic loader.
+  programs.nix-ld.enable = true;
 
   environment.systemPackages = with pkgs; [
     nixfmt
     pi-coding-agent
+    # Runtime build prerequisites for the unchanged Lazy/Mason plugin workflow.
+    gcc
+    gnumake
+    pkg-config
+    python3
+    nodejs
+    lua5_1
+    luajitPackages.luarocks
     ripgrep
     fd
     eza