navigate_back · PageMap MCP: Risk & Policy

WHAT IT DOES

What navigate_back does on PageMap

AI agents invoke navigate_back to trigger actions in PageMap. 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 navigate_back needs a policy

Navigation is a browser control action that changes the displayed page and can trigger page load side effects (scripts, external requests, etc.). It is not a simple Read operation (it modifies browser state), but it is reversible (forward navigation undoes it) and not destructive. This qualifies as Execute: it performs an external operation (browser history navigation) whose consequences depend on context.

From the tool's definition Tool description states 'Navigate back to the previous page in browser history' — this triggers a browser navigation action whose effects depend on the current page's history stack.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

navigate_back Rate-limited

navigate_back 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": {
    "navigate_back": {
      "limits": [
        {
          "counter": "navigate_back_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 PageMap, so you can run agents against it safely.

FAQ

Questions about navigate_back

What does the navigate_back tool do? +

Navigate back to the previous page in browser history. It is categorised as a Execute tool in the PageMap MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on navigate_back? +

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

What risk level is navigate_back? +

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

Can I rate-limit navigate_back? +

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

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

navigate_back is provided by the PageMap MCP server (oci:docker.io/retio1001/pagemap:0.7.3). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.