replace_lines_in_file · MCP File Editor Server MCP

WHAT IT DOES

What replace_lines_in_file does on MCP File Editor Server

AI agents use replace_lines_in_file to create or update resources in MCP File Editor Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP File Editor Server environment.

WHY IT NEEDS A POLICY

Why replace_lines_in_file needs a policy

This tool modifies file content but does not permanently delete data or make irreversible changes—the replaced content could theoretically be recovered from backups or version control. It is categorized as Write rather than Destructive because replacement is reversible in nature (the old content is overwritten but not purged from system backups).

From the tool's definition Tool name 'replace_lines_in_file' and description 'Replace content between specific line numbers in a file' indicate modification of file content.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

replace_lines_in_file Rate-limited

replace_lines_in_file stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "replace_lines_in_file": {
      "limits": [
        {
          "counter": "replace_lines_in_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches MCP File Editor Server, so you can run agents against it safely.

FAQ

Questions about replace_lines_in_file

What does the replace_lines_in_file tool do? +

Replace content between specific line numbers in a file. It is categorised as a Write tool in the MCP File Editor Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on replace_lines_in_file? +

Register the MCP File Editor Server MCP server in PolicyLayer and add a rule for replace_lines_in_file: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches MCP File Editor Server. Nothing to install.

What risk level is replace_lines_in_file? +

replace_lines_in_file is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit replace_lines_in_file? +

Yes. Add a rate_limit block to the replace_lines_in_file rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block replace_lines_in_file completely? +

Set action: deny in the PolicyLayer policy for replace_lines_in_file. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides replace_lines_in_file? +

replace_lines_in_file is provided by the MCP File Editor Server MCP server (pwilkin/mcp-file-edit). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.