error_tool

A tool that always returns an error

SERVERGenkit MCP SOURCEgenkit-ai/genkit

Low RISK CLASS

Category Other

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/firebase-genkit/error-tool.md

WHAT IT DOES

What error_tool does on Genkit MCP

AI agents call error_tool as a supporting operation in Genkit MCP workflows.

RISK

Why error_tool is rated Low

This tool is described as always returning an error, meaning it has no successful side effects — it cannot read, write, execute, destroy, or transact anything. It appears to be a test/diagnostic tool for error-handling scenarios. Since it always fails, its blast radius is effectively zero.

From the tool's definition A tool that always returns an error

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs error_tool safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Genkit MCP, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For error_tool, this is the rule to start with:

error_tool Rate-limited

error_tool gets a rate cap, and everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "error_tool": {
      "limits": [
        {
          "counter": "error_tool_rate",
          "window": "minute",
          "max": 60,
          "scope": "grant"
        }
      ]
    }
  }
}

SET A RULE FOR THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Genkit MCP, apply this rule, and every error_tool call is checked against it from then on.

FAQ

Questions about error_tool

What does the error_tool tool do? +

A tool that always returns an error. It is categorised as a Other tool in the Genkit MCP MCP Server, which means it performs auxiliary operations.

How do I enforce a policy on error_tool? +

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

What risk level is error_tool? +

error_tool is a Other tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit error_tool? +

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

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

error_tool is provided by the Genkit MCP server (genkit-ai/genkit). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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