diff --git a/internal/agent/tools/bash.tpl b/internal/agent/tools/bash.tpl
index 3663158afa7cd7a6e4d90b2468373096fa7ccf0e..2d9999b849785b900b424eff27917f29e6d97f8e 100644
--- a/internal/agent/tools/bash.tpl
+++ b/internal/agent/tools/bash.tpl
@@ -1,5 +1,10 @@
 Execute shell commands; long-running commands automatically move to background and return a shell ID.
 
+<cross_platform>
+Uses mvdan/sh interpreter (Bash-compatible on all platforms including Windows).
+Use forward slashes for paths: "ls C:/foo/bar" not "ls C:\foo\bar".
+Common shell builtins and core utils available on Windows.
+</cross_platform>
 
 <execution_steps>
 1. Directory Verification: If creating directories/files, use LS tool to verify parent exists