AI agents use save-ui-hierarchy to create or update resources in MCP Appium Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP Appium Server environment.
This tool writes data to a file, which is a reversible operation (files can be deleted or overwritten). It does not delete data irreversibly (not Destructive), does not execute arbitrary code or commands (not Execute), and does not involve financial transactions (not Financial).
From the tool's definition Tool name 'save-ui-hierarchy' and description 'Save UI hierarchy XML to a file' indicate file creation/writing operations. The tool creates or persists data (UI hierarchy XML) to the filesystem.
Documented attack patterns abuse exactly the kind of access save-ui-hierarchy gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP Appium Server, and nothing reaches the server without passing your rules. This is the rule we recommend for save-ui-hierarchy:
{
"version": "1",
"default": "deny",
"tools": {
"save-ui-hierarchy": {
"limits": [
{
"counter": "save-ui-hierarchy_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}save-ui-hierarchy 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.
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Save UI hierarchy XML to a file. It is categorised as a Write tool in the MCP Appium Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the MCP Appium Server MCP server in PolicyLayer and add a rule for save-ui-hierarchy: 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 MCP Appium Server. Nothing to install.
save-ui-hierarchy is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the save-ui-hierarchy 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 save-ui-hierarchy. 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.
save-ui-hierarchy is provided by the MCP Appium Server MCP server (rahulec08/appium-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 110 MCP Appium Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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110 MCP Appium Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.