Check bundle size of a package
AI agents call check_bundle_size 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 performs a read-only inspection of package metadata (bundle size statistics). It retrieves information from npm or similar registries without side effects, reversible changes, code execution, or destructive operations. The sibling tools include other read operations (analyze_dependencies, audit_dependencies, download_stats) that follow the same pattern.
From the tool's definition Tool name 'check_bundle_size' and description 'Check bundle size of a package' indicate a query operation that retrieves and reports metrics about a package without modifying, executing, or deleting anything.
Documented attack patterns abuse exactly the kind of access check_bundle_size 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_bundle_size:
{
"version": "1",
"default": "deny",
"tools": {
"check_bundle_size": {}
}
}check_bundle_size is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Check bundle size of a package. 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_bundle_size: 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_bundle_size 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_bundle_size 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_bundle_size. 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_bundle_size 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.