Show ${hiddenCount} additional specialist tools (network, emulation, PDF, orchestration, etc). Call with tier=2 for specialist tools, tier=3 for all tools including orchestration.
AI agents call expand_tools to retrieve information from OpenChrome without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool simply reveals/lists additional tools available on the server. It is a discovery/read operation with no side effects on the browser, data, or external systems. The worst case misuse is an agent learning about more powerful tools, but the tool itself only reads/displays metadata.
From the tool's definition 'Show ${hiddenCount} additional specialist tools' — retrieves/displays a list of available tools
Documented attack patterns abuse exactly the kind of access expand_tools gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and OpenChrome, and nothing reaches the server without passing your rules. This is the rule we recommend for expand_tools:
{
"version": "1",
"default": "deny",
"tools": {
"expand_tools": {}
}
}expand_tools 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.
Show ${hiddenCount} additional specialist tools (network, emulation, PDF, orchestration, etc). Call with tier=2 for specialist tools, tier=3 for all tools including orchestration. It is categorised as a Read tool in the OpenChrome MCP Server, which means it retrieves data without modifying state.
Register the OpenChrome MCP server in PolicyLayer and add a rule for expand_tools: 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 OpenChrome. Nothing to install.
expand_tools 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 expand_tools 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 expand_tools. 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.
expand_tools is provided by the OpenChrome MCP server (shaun0927/openchrome). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 106 OpenChrome tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
106 OpenChrome tools catalogued and risk-classified — across an index of 42,500+ MCP servers.