trigger_extension_action · Chrome Devtools MCP

WHAT IT DOES

What trigger_extension_action does on Chrome Devtools

AI agents invoke trigger_extension_action to trigger actions in Chrome Devtools. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why trigger_extension_action needs a policy

This tool executes code with side effects by invoking extension functionality. While the exact consequences depend on which extension is targeted and its permissions, extensions can perform reads, writes, destructive operations, and access sensitive browser APIs. The tool itself enables execution of arbitrary extension logic, making it Execute category.

From the tool's definition Triggers the default action of an extension by its ID. Extensions can perform arbitrary operations including network requests, data access, DOM manipulation, and system-level actions depending on their permissions and implementation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

trigger_extension_action Rate-limited

trigger_extension_action stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "trigger_extension_action": {
      "limits": [
        {
          "counter": "trigger_extension_action_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Chrome Devtools, so you can run agents against it safely.

FAQ

Questions about trigger_extension_action

What does the trigger_extension_action tool do? +

Triggers the default action of an extension by its ID. It is categorised as a Execute tool in the Chrome Devtools MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on trigger_extension_action? +

Register the Chrome Devtools MCP server in PolicyLayer and add a rule for trigger_extension_action: 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 Chrome Devtools. Nothing to install.

What risk level is trigger_extension_action? +

trigger_extension_action is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit trigger_extension_action? +

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

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

trigger_extension_action is provided by the Chrome Devtools MCP server (zhang77-x/chrpme_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.