set_font_scale · Enhanced ADB MCP Server MCP: Risk & Policy

WHAT IT DOES

What set_font_scale does on Enhanced ADB MCP Server

AI agents use set_font_scale to create or update resources in Enhanced ADB MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Enhanced ADB MCP Server environment.

WHY IT NEEDS A POLICY

Why set_font_scale needs a policy

This tool modifies device configuration state (font scale), which is a reversible Write operation. While it affects system behavior, changes can be undone by resetting to default or another value. It has no destructive effect, does not execute arbitrary code, and carries minimal blast radius if misused (worst case: poor readability until reset).

From the tool's definition Tool sets/modifies system-level font scale parameter with values (0.85, 1.0, 1.15, 1.3). The description explicitly indicates it 'Set[s]' a system configuration setting.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_font_scale Rate-limited

set_font_scale stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "set_font_scale": {
      "limits": [
        {
          "counter": "set_font_scale_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about set_font_scale

What does the set_font_scale tool do? +

Set system font scale (0.85 = small, 1.0 = normal, 1.15 = large, 1.3 = largest). It is categorised as a Write tool in the Enhanced ADB MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_font_scale? +

Register the Enhanced ADB MCP Server MCP server in PolicyLayer and add a rule for set_font_scale: 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 Enhanced ADB MCP Server. Nothing to install.

What risk level is set_font_scale? +

set_font_scale is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit set_font_scale? +

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

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

set_font_scale is provided by the Enhanced ADB MCP Server MCP server (rahulkr/r_adb_mcp_server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.