app_error · Goose App Maker MCP: Risk & Policy

WHAT IT DOES

What app_error does on Goose App Maker MCP

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

WHY IT NEEDS A POLICY

Why app_error needs a policy

An AI agent can call app_error faster than any human can review — one bad instruction and it creates or modifies resources in Goose App Maker MCP by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

app_error Rate-limited

app_error 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": {
    "app_error": {
      "limits": [
        {
          "counter": "app_error_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 Goose App Maker MCP, so you can run agents against it safely.

FAQ

Questions about app_error

What does the app_error tool do? +

app_error. It is categorised as a Write tool in the Goose App Maker 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 app_error? +

Register the Goose App Maker MCP server in PolicyLayer and add a rule for app_error: 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 Goose App Maker MCP. Nothing to install.

What risk level is app_error? +

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

Can I rate-limit app_error? +

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

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

app_error is provided by the Goose App Maker MCP server (michaelneale/goose-app-maker-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

// THE FULL RECORD

app_error is one line of Goose App Maker's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

Teams ship this data inside their own products. See what a licence covers →