switch_tab · WebScout MCP: Risk & Policy

WHAT IT DOES

What switch_tab does on WebScout MCP

AI agents invoke switch_tab to trigger actions in WebScout MCP. 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 switch_tab needs a policy

This tool performs a browser automation action (switching active tabs), which is an Execute-category operation. It controls browser state and enables subsequent interactions with different web pages. While the immediate action of switching tabs is relatively benign, it can redirect agent focus to arbitrary pages and enable further automated interactions, giving it medium severity.

From the tool's definition Switch the active browser tab when multiple tabs are open in the session... clicking a link that opens a chat in a new tab requires switching to that tab to interact with it

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

switch_tab Rate-limited

switch_tab 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": {
    "switch_tab": {
      "limits": [
        {
          "counter": "switch_tab_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 WebScout MCP, so you can run agents against it safely.

FAQ

Questions about switch_tab

What does the switch_tab tool do? +

Switch the active browser tab when multiple tabs are open in the session. Common scenario: clicking a link that opens a chat in a new tab requires switching to that tab to interact with it. Use get_current_page_info first to see all available tabs and their indices. It is categorised as a Execute tool in the WebScout MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on switch_tab? +

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

What risk level is switch_tab? +

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

Can I rate-limit switch_tab? +

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

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

switch_tab is provided by the WebScout MCP server (pyscout/webscout-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.