file_generate · Tools MCP: Risk & Policy

WHAT IT DOES

What file_generate does on Tools

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

PARAMETERS

Parameter	Type	Required	Description
`data`	array	Yes	Array of objects to generate file from
`format`	string	Yes	Output format (default: csv)
`options`	object	—

Parameters from the server's own tool schema.

WHY IT NEEDS A POLICY

Why file_generate needs a policy

This tool creates new files programmatically, which is a Write operation. Severity is medium because while file generation is reversible and the blast radius is limited to file creation, an AI agent could generate numerous files, consume storage resources, or create files with malicious content for later use.

From the tool's definition Tool generates and returns files in CSV/TSV/JSON formats from structured data. The description explicitly states 'Generate... file' and 'Returns base64-encoded file and raw text', indicating file creation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

file_generate Rate-limited

file_generate 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": {
    "file_generate": {
      "limits": [
        {
          "counter": "file_generate_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 Tools, so you can run agents against it safely.

FAQ

Questions about file_generate

What does the file_generate tool do? +

Generate CSV/TSV/JSON file from structured data array. Returns base64-encoded file and raw text. It is categorised as a Write tool in the Tools MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does file_generate accept? +

file_generate accepts 3 parameters: data, format, options. Required: data, format. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on file_generate? +

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

What risk level is file_generate? +

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

Can I rate-limit file_generate? +

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

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

file_generate is provided by the Tools MCP server (https://www.jiebang.site/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.