update_file · SACL MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_file does on SACL MCP Server

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

WHY IT NEEDS A POLICY

Why update_file needs a policy

This tool performs a write operation that modifies file analysis data. It is reversible (analysis can be recomputed or reverted) and does not delete data, making it Write rather than Destructive.

From the tool's definition Tool description states 'Update single file analysis when changes are made (explicit agent-controlled)'. The verb 'Update' and context of 'when changes are made' indicate this tool modifies existing data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_file Rate-limited

update_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": {
    "update_file": {
      "limits": [
        {
          "counter": "update_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about update_file

What does the update_file tool do? +

Update single file analysis when changes are made (explicit agent-controlled). It is categorised as a Write tool in the SACL MCP 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 update_file? +

Register the SACL MCP Server MCP server in PolicyLayer and add a rule for update_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 SACL MCP Server. Nothing to install.

What risk level is update_file? +

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

Can I rate-limit update_file? +

Yes. Add a rate_limit block to the update_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 update_file completely? +

Set action: deny in the PolicyLayer policy for update_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 update_file? +

update_file is provided by the SACL MCP Server MCP server (ulasbilgen/sacl). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.