extract_variables

Identify and weight the key variables driving an entity

SERVERNodebench SOURCEnodebench-mcp

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-homenshum-nodebench/extract-variables.md

WHAT IT DOES

What extract_variables does on Nodebench

AI agents call extract_variables to retrieve information from Nodebench without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why extract_variables is rated Low

The tool performs data analysis and extraction of variables from an entity without modifying, deleting, or executing arbitrary operations. It returns insights derived from existing data, making it a Read operation. The narrow, analytical scope and lack of side effects justify low severity.

From the tool's definition Tool description states 'Identify and weight the key variables' — this is an analysis and identification task with no mutations to data. The verb 'extract' combined with 'identify' indicates retrieval and analysis of information from existing data.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs extract_variables safely

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

extract_variables Allowed

extract_variables is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "extract_variables": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

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

FAQ

Questions about extract_variables

What does the extract_variables tool do? +

Identify and weight the key variables driving an entity. It is categorised as a Read tool in the Nodebench MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on extract_variables? +

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

What risk level is extract_variables? +

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

Can I rate-limit extract_variables? +

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

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

extract_variables is provided by the Nodebench MCP server (nodebench-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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