prefer_write_tool

Block bash file operations, remind agent to use proper tools instead

Problem

AI models often use bash commands for file operations:

File Creation

code

cat <<EOF > /tmp/my_script.py
import os
print("hello")
EOF

File Reading

code

cat config.json
head -n 10 README.md

Why This is an Anti-Pattern

•Bypasses proper tool UI/diffs/approval flow
•Escaping issues with special characters
•Harder to review and track changes
•No line numbers or formatting for reading

Solution

This plugin detects bash file operations before execution and rejects them with a system reminder telling the agent to use the proper tools (read_file, write, edit).

main.py

from connectonion import Agent
from connectonion.useful_plugins import prefer_write_tool

agent = Agent(
    "assistant",
    tools=[bash, read_file, write, edit],
    plugins=[prefer_write_tool]
)

Detected Patterns

File Creation (blocked)

•cat <<EOF > file.py - heredoc redirection

•echo "..." > file.py - output redirection

•printf "..." > file.py - printf redirection

•cmd > file - any output redirection

•cmd >> file - append redirection

•tee file.py - tee command

File Reading (blocked)

•cat file.txt - read file contents

•head file.txt - read first lines

•tail file.log - read last lines

•less file.txt - page through file

•more file.txt - page through file

What Happens

When detected, the tool is rejected and the agent receives a system reminder:

For file creation

Bash file creation blocked.

<system-reminder>
You tried to create a file using bash. This is blocked.

Use the Write tool instead:
  Write(file_path="/path/to/file.py", content="...")

For editing existing files:
  Edit(file_path="/path/to/file.py", old_string="...", new_string="...")
</system-reminder>

For file reading

Bash file reading blocked.

<system-reminder>
You tried to read a file using bash. This is blocked.

Use the read_file tool instead:
  read_file(file_path="/path/to/file.txt")

Why: read_file provides line numbers, proper formatting, and better control.
</system-reminder>

Result

The agent will then use the proper tools (read_file, write, edit).

Combining with tool_approval

You can use both plugins together: