fs_read_file

Read a text file inside the allowlist. If the file is an image (PNG, JPEG, GIF, WebP, SVG), it will be automatically read and returned as an image block.

SERVERLocalAnt SOURCEyuga-hashimoto/localant

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/yuga-hashimoto-localant/fs-read-file.md

WHAT IT DOES

What fs_read_file does on LocalAnt

AI agents call fs_read_file to retrieve information from LocalAnt without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why fs_read_file is rated Low

This tool retrieves file contents from pre-approved files only. There is no modification, deletion, execution, or financial impact. The allowlist restriction further limits risk. This is a straightforward read operation with minimal blast radius — an agent could learn file contents but cannot alter system state.

From the tool's definition Tool name is 'fs_read_file' and description states 'Read a text file inside the allowlist' — the verb 'Read' and reference to an allowlist (which restricts scope) clearly indicate data retrieval with no side effects.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs fs_read_file safely

PolicyLayer is an MCP gateway: it sits between your AI agents and LocalAnt, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For fs_read_file, this is the rule to start with:

fs_read_file Allowed

fs_read_file is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "fs_read_file": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect LocalAnt, apply this rule, and every fs_read_file call is checked against it from then on.

FAQ

Questions about fs_read_file

What does the fs_read_file tool do? +

Read a text file inside the allowlist. If the file is an image (PNG, JPEG, GIF, WebP, SVG), it will be automatically read and returned as an image block. It is categorised as a Read tool in the LocalAnt MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on fs_read_file? +

Register the LocalAnt MCP server in PolicyLayer and add a rule for fs_read_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 LocalAnt. Nothing to install.

What risk level is fs_read_file? +

fs_read_file is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit fs_read_file? +

Yes. Add a rate_limit block to the fs_read_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.

How do I block fs_read_file completely? +

Set action: deny in the PolicyLayer policy for fs_read_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.

What MCP server provides fs_read_file? +

fs_read_file is provided by the LocalAnt MCP server (yuga-hashimoto/localant). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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