clean_cache

THE RISK

Critical Risk

Why clean_cache needs a policy

Cleaning a cache permanently removes cached package data that cannot be recovered without re-downloading. This is an irreversible deletion operation (Destructive). The blast radius is medium since it deletes cached files but doesn't affect installed packages or project code directly; the main consequence is slower subsequent installs as caches must be rebuilt.

From the tool's definition 'Clean package manager cache' - cleaning/purging cache is an irreversible deletion of cached data

Documented attack patterns abuse exactly the kind of access clean_cache gives an agent:

POLICY

How to control clean_cache

PolicyLayer is an MCP gateway — it sits between your AI agents and Npmplus, and nothing reaches the server without passing your rules. This is the rule we recommend for clean_cache:

policy.json

{
  "version": "1",
  "default": "deny",
  "hide": [
    "clean_cache"
  ]
}

clean_cache disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.

Create a free account and register Npmplus — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RESTRICT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Npmplus tools

Destructive remove_packages Remove npm packages Write install_packages Install npm packages Write update_packages Update npm packages Read analyze_dependencies Analyze project dependencies (provide either cwd path or package.json content) Read audit_dependencies Audit dependencies for vulnerabilities (provide either cwd path or package.json content) Read check_bundle_size Check bundle size of a package Read check_license Check package license Read check_outdated Check for outdated packages (provide either cwd path or package.json content)

All 16 Npmplus tools →

Destructive tools on other servers

Android Forensics ADB MCP Server create_full_backup 0xarchive web3_revoke_key Frida Game Hacking MCP clear_scan cPanel MCP Server clear_spam_box

Go deeper

Critical-risk tools in Npmplus → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Blast radius → How much damage one compromised or confused agent can do — and how to bound it.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about clean_cache

What does the clean_cache tool do? +

Clean package manager cache. It is categorised as a Destructive tool in the Npmplus MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.

How do I enforce a policy on clean_cache? +

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

What risk level is clean_cache? +

clean_cache is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit clean_cache? +

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

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

clean_cache is provided by the Npmplus MCP server (shacharsol/js-package-manager-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Npmplus tool call.

Start from Npmplus, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →