docs: added explanation for the 2>/dev/tty for bash built-in script tool usage

Bash-Prompt-Helpers.md

@@ -28,6 +28,27 @@ scripts:
 source "$LLM_PROMPT_UTILS_FILE"
 ```
 
+# Why Examples Use `2>/dev/tty`
+Coyote runs each tool as a subprocess and **captures the tool's stderr** into a buffer. When the wrapped command exits
+non-zero, that buffer is attached to the tool result returned to the LLM as `error_json["stderr"]`.
+
+All the interactive helpers below (`input`, `confirm`, `list`, `checkbox`, `password`, etc.) write their prompt text and
+terminal escape sequences to stderr. Without redirection, the prompt leaks into the LLM-visible error JSON the next time
+your tool exits non-zero, which can produce hallucinations where the model "sees" a confirmation prompt that was meant 
+for the user.
+
+**The fix is to send the helper's stderr straight to the user's terminal:**
+
+```bash
+answer=$(confirm "Proceed?" 2>/dev/tty)
+```
+
+Helpers read user input from `/dev/tty` directly, so the redirect only affects the *output* (the prompt itself). Every
+example below uses this pattern. Copy it as-is whenever you wrap a helper in `$(...)`.
+
+> `guard_operation` and `guard_path` already apply this redirect internally so you do **not** need `2>/dev/tty` when
+> calling them.
+
 # Included Utility Functions
 Below are the built-in bash prompt helpers that can be used to enhance user interaction with your tool scripts.