sdk_focus · UI Bridge MCP: Risk & Policy

WHAT IT DOES

What sdk_focus does on UI Bridge MCP

AI agents invoke sdk_focus to trigger actions in UI Bridge 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 sdk_focus needs a policy

Focusing a UI element triggers an external UI interaction/operation in the SDK application. This is not a passive read — it actively changes the state of the UI (focus state of an element), making it an Execute-level action. Misuse could cause unintended UI interactions or disrupt user workflows.

From the tool's definition Focus an element in the SDK app

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

sdk_focus Rate-limited

sdk_focus 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": {
    "sdk_focus": {
      "limits": [
        {
          "counter": "sdk_focus_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 UI Bridge MCP, so you can run agents against it safely.

FAQ

Questions about sdk_focus

What does the sdk_focus tool do? +

Focus an element in the SDK app. It is categorised as a Execute tool in the UI Bridge 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 sdk_focus? +

Register the UI Bridge MCP server in PolicyLayer and add a rule for sdk_focus: 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 UI Bridge MCP. Nothing to install.

What risk level is sdk_focus? +

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

Can I rate-limit sdk_focus? +

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

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

sdk_focus is provided by the UI Bridge MCP server (qontinui/ui-bridge-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.