Checks if a file or directory exists at the specified path.
AI agents call check_file_exists to retrieve information from Xcode without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves existence status of a file or directory without modifying, creating, or deleting any data. It is a pure read operation analogous to a filesystem stat or ls command used for discovery. No destructive or state-changing actions are possible.
From the tool's definition Tool name 'check_file_exists' and description 'Checks if a file or directory exists at the specified path' indicate a query operation with no side effects.
Documented attack patterns abuse exactly the kind of access check_file_exists gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Xcode, and nothing reaches the server without passing your rules. This is the rule we recommend for check_file_exists:
{
"version": "1",
"default": "deny",
"tools": {
"check_file_exists": {}
}
}check_file_exists is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Checks if a file or directory exists at the specified path. It is categorised as a Read tool in the Xcode MCP Server, which means it retrieves data without modifying state.
Register the Xcode MCP server in PolicyLayer and add a rule for check_file_exists: 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 Xcode. Nothing to install.
check_file_exists is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the check_file_exists 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 check_file_exists. 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.
check_file_exists is provided by the Xcode MCP server (xcode-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 69 Xcode tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
69 Xcode tools catalogued and risk-classified — across an index of 42,500+ MCP servers.