List files in a directory
AI agents call list_files to retrieve information from MCP Filesystem Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves directory contents and metadata but performs no side effects, modifications, or deletions. It is a pure read operation with minimal blast radius even if misused by an agent, as it cannot alter system state or expose sensitive file contents directly—only directory structure. Classified as Read/low severity.
From the tool's definition Tool name 'list_files' and description 'List files in a directory' indicate a directory listing operation with no modification of data. The server description groups this with 'list' operations, a classic Read category example.
Attacks that exploit this kind of access
List files in a directory. It is categorised as a Read tool in the MCP Filesystem Server MCP Server, which means it retrieves data without modifying state.
Register the MCP Filesystem Server MCP server in PolicyLayer and add a rule for list_files: 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 Filesystem Server. Nothing to install.
list_files 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 list_files 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 list_files. 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.
list_files is provided by the MCP Filesystem Server MCP server (midsane/mcp). 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 →