superskills_write_file · Superskills MCP: Risk & Policy

WHAT IT DOES

What superskills_write_file does on Superskills

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

WHY IT NEEDS A POLICY

Why superskills_write_file needs a policy

This tool creates or modifies files with automatic parent directory creation. While overwriting is reversible (classifying it as Write rather than Destructive), the high severity reflects that an AI agent could overwrite critical configuration files, source code, or other important local data without explicit consent. The blast radius is substantial in a local environment where file system access is sensitive.

From the tool's definition Tool description explicitly states 'Write content to a local file' and 'Overwrites existing files.' The mechanism is reversible (files can be rewritten or deleted by other means) but the overwrite capability poses significant risk.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

superskills_write_file Rate-limited

superskills_write_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": {
    "superskills_write_file": {
      "limits": [
        {
          "counter": "superskills_write_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 Superskills, so you can run agents against it safely.

FAQ

Questions about superskills_write_file

What does the superskills_write_file tool do? +

Write content to a local file, creating parent directories automatically. Overwrites existing files. It is categorised as a Write tool in the Superskills MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on superskills_write_file? +

Register the Superskills MCP server in PolicyLayer and add a rule for superskills_write_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 Superskills. Nothing to install.

What risk level is superskills_write_file? +

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

Can I rate-limit superskills_write_file? +

Yes. Add a rate_limit block to the superskills_write_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 superskills_write_file completely? +

Set action: deny in the PolicyLayer policy for superskills_write_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 superskills_write_file? +

superskills_write_file is provided by the Superskills MCP server (lee2026-dev/superskills-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.