fs_read_file_range

Read a line range from a file (1-indexed, inclusive).

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-range.md

WHAT IT DOES

What fs_read_file_range does on LocalAnt

AI agents call fs_read_file_range 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_range is rated Low

This tool retrieves file contents within a specified line range. It performs a query operation on local files without modifying, deleting, or executing anything. The 1-indexed inclusive range specification confirms it is a read-only operation. Severity is low because reading file contents poses minimal risk even if misused by an AI agent—the worst case is information disclosure of data the user already has access to.

From the tool's definition Tool name 'fs_read_file_range' and description 'Read a line range from a file' explicitly indicate data retrieval with no side effects.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs fs_read_file_range 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_range, this is the rule to start with:

fs_read_file_range Allowed

fs_read_file_range 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_range": {}
  }
}

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_range call is checked against it from then on.

FAQ

Questions about fs_read_file_range

What does the fs_read_file_range tool do? +

Read a line range from a file (1-indexed, inclusive). 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_range? +

Register the LocalAnt MCP server in PolicyLayer and add a rule for fs_read_file_range: 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_range? +

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

Can I rate-limit fs_read_file_range? +

Yes. Add a rate_limit block to the fs_read_file_range 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_range completely? +

Set action: deny in the PolicyLayer policy for fs_read_file_range. 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_range? +

fs_read_file_range 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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