AI agents call open_file to retrieve information from Markview without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool opens a file for viewing/previewing in a markdown viewer application. It reads an existing file from disk and displays it — no data is created, modified, or deleted. The primary action is reading/fetching file content for display purposes. Severity is low as the worst case is opening an unintended file in a viewer.
From the tool's definition Open an existing markdown file from disk in MarkView
Attacks that exploit this kind of access
Open an existing markdown file from disk in MarkView. It is categorised as a Read tool in the Markview MCP Server, which means it retrieves data without modifying state.
Register the Markview MCP server in PolicyLayer and add a rule for open_file: 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 Markview. Nothing to install.
open_file 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 open_file 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 open_file. 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.
open_file is provided by the Markview MCP server (mcp-server-markview). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →