save_files · Vigentic MCP: Risk & Policy

WHAT IT DOES

What save_files does on Vigentic MCP

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

WHY IT NEEDS A POLICY

Why save_files needs a policy

This tool creates or modifies data reversibly by saving file buffers to disk. It is categorized as Write rather than Execute because the action is a standard file persistence operation, not code execution or command triggering. The severity is medium because unintended saves could overwrite file contents, though the operation is reversible (via version control or undo).

From the tool's definition The tool description explicitly states 'Save only the requested open file buffers', which performs a write operation that modifies files on disk by persisting buffer contents to their stored locations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

save_files Rate-limited

save_files 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": {
    "save_files": {
      "limits": [
        {
          "counter": "save_files_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 Vigentic MCP, so you can run agents against it safely.

FAQ

Questions about save_files

What does the save_files tool do? +

Save only the requested open file buffers and record fresh saved-state metadata. It is categorised as a Write tool in the Vigentic MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on save_files? +

Register the Vigentic MCP server in PolicyLayer and add a rule for save_files: 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 Vigentic MCP. Nothing to install.

What risk level is save_files? +

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

Can I rate-limit save_files? +

Yes. Add a rate_limit block to the save_files 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 save_files completely? +

Set action: deny in the PolicyLayer policy for save_files. 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 save_files? +

save_files is provided by the Vigentic MCP server (munozu/vigentic-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.