gem-list

Lists installed Ruby gems with version information. Returns structured JSON with gem names and versions.

SERVERCargo SOURCEDave-London/Pare

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-dave-london-cargo/gem-list.md

WHAT IT DOES

What gem-list does on Cargo

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

RISK

Why gem-list is rated Low

This tool is a read-only query of the local Ruby gem installation. It gathers inventory data (gem names, versions) without side effects. The blast radius of misuse is minimal — an AI agent could at most learn what gems are installed, which is informational only. No write, execute, destructive, or financial operations are possible.

From the tool's definition The tool 'Lists installed Ruby gems with version information' and 'Returns structured JSON with gem names and versions' — it retrieves and queries system state without modifying or executing anything.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs gem-list safely

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

gem-list Allowed

gem-list 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": {
    "gem-list": {}
  }
}

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

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

FAQ

Questions about gem-list

What does the gem-list tool do? +

Lists installed Ruby gems with version information. Returns structured JSON with gem names and versions. It is categorised as a Read tool in the Cargo MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on gem-list? +

Register the Cargo MCP server in PolicyLayer and add a rule for gem-list: 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 Cargo. Nothing to install.

What risk level is gem-list? +

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

Can I rate-limit gem-list? +

Yes. Add a rate_limit block to the gem-list 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 gem-list completely? +

Set action: deny in the PolicyLayer policy for gem-list. 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 gem-list? +

gem-list is provided by the Cargo MCP server (Dave-London/Pare). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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