Check for outdated packages (provide either cwd path or package.json content)
AI agents call check_outdated to retrieve information from Npmplus without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and compares package version information to identify outdated dependencies. It performs no writes, deletions, installations, or external operations—purely informational querying. It has no side effects on the package ecosystem or system state. Severity is low because misuse (e.g., checking a malicious package.json) poses minimal risk; the worst outcome is misleading version data.
From the tool's definition Tool name 'check_outdated' and description 'Check for outdated packages' indicates a query/reporting operation that inspects package versions without modifying state. Input is either a working directory path or package.json content for analysis.
Documented attack patterns abuse exactly the kind of access check_outdated gives an agent:
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 check_outdated:
{
"version": "1",
"default": "deny",
"tools": {
"check_outdated": {}
}
}check_outdated is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Check for outdated packages (provide either cwd path or package.json content). It is categorised as a Read tool in the Npmplus MCP Server, which means it retrieves data without modifying state.
Register the Npmplus MCP server in PolicyLayer and add a rule for check_outdated: 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.
check_outdated is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the check_outdated 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.
Set action: deny in the PolicyLayer policy for check_outdated. 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.
check_outdated 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.
Start from Npmplus, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
16 Npmplus tools catalogued and risk-classified — across an index of 43,000+ MCP servers.