json_format · Devutils MCP: Risk & Policy

WHAT IT DOES

What json_format does on Devutils

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

WHY IT NEEDS A POLICY

Why json_format needs a policy

The tool creates or modifies data (JSON formatting/minification) in a reversible manner. It does not delete data (ruling out Destructive), execute arbitrary operations (ruling out Execute), access external systems (ruling out Financial), or have significant side effects. The severity is low because formatting changes are easily reversible and have minimal blast radius if misused by an agent.

From the tool's definition Tool description states it can 'Format (pretty-print) a JSON string' and 'minify JSON', which are reversible transformations that modify the structure of JSON data without deleting or executing code.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

json_format Rate-limited

json_format 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": {
    "json_format": {
      "limits": [
        {
          "counter": "json_format_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 Devutils, so you can run agents against it safely.

FAQ

Questions about json_format

What does the json_format tool do? +

Format (pretty-print) a JSON string with configurable indentation. Can also minify JSON. It is categorised as a Write tool in the Devutils MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on json_format? +

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

What risk level is json_format? +

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

Can I rate-limit json_format? +

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

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

json_format is provided by the Devutils MCP server (paladini/devutils-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.