AI agents invoke browser_resize to trigger actions in Playwright MCP with Electron Support. 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.
Resizing a browser window is a side-effecting operation that modifies the state of a running browser or Electron application process. It doesn't read data, write persistent data, or destroy anything, but it does trigger an external operation whose effect depends on the provided dimensions. Severity is low because the blast radius of misuse is minimal — worst case is an inconvenient window size.
From the tool's definition 'Resize the browser window' — triggers an external operation (window geometry change) in a live browser or Electron process
Documented attack patterns abuse exactly the kind of access browser_resize gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Playwright MCP with Electron Support, and nothing reaches the server without passing your rules. This is the rule we recommend for browser_resize:
{
"version": "1",
"default": "deny",
"tools": {
"browser_resize": {
"limits": [
{
"counter": "browser_resize_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}browser_resize 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.
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Resize the browser window. It is categorised as a Execute tool in the Playwright MCP with Electron Support MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Playwright MCP with Electron Support MCP server in PolicyLayer and add a rule for browser_resize: 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 Playwright MCP with Electron Support. Nothing to install.
browser_resize is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the browser_resize 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 browser_resize. 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.
browser_resize is provided by the Playwright MCP with Electron Support MCP server (robertn702/playwright-mcp-electron). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Playwright MCP with Electron Support, 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.
34 Playwright MCP with Electron Support tools catalogued and risk-classified — across an index of 43,000+ MCP servers.