diff --git a/shared/global-instructions.md b/shared/global-instructions.md
index 78c82fd..ec70e0b 100644
--- a/shared/global-instructions.md
+++ b/shared/global-instructions.md
@@ -1,6 +1,6 @@
 # Global Instructions
 
-Read `~/.my-ai-configuration/instructions/__CLIENT__.md` first when present; it is the user's direct instruction. System and developer requirements still apply.
+Optional personal instructions: first check whether `~/.my-ai-configuration/instructions/__CLIENT__.md` is a file (`Test-Path -LiteralPath ... -PathType Leaf` in PowerShell; `test -f ...` in Bash). Read it only if it exists; otherwise continue silently. Its contents are the user's direct instructions. System and developer requirements still apply.
 
 For credentials, run the child command through `~/.my-ai-configuration/bin/with-credential.__SHELL__` with the client and credential key. Never expose credentials in commands, output, logs, or files.