review_code

THE RISK

Low Risk

Why review_code needs a policy

Code review is fundamentally an analytical operation that retrieves and examines code to provide feedback. It does not modify data (not Write), execute arbitrary code (not Execute), delete anything (not Destructive), or involve financial operations (not Financial).

From the tool's definition Tool name 'review_code' and description 'Reviews the given code' indicate a read-only operation that analyzes code without modification or execution.

Documented attack patterns abuse exactly the kind of access review_code gives an agent:

POLICY

How to control review_code

PolicyLayer is an MCP gateway — it sits between your AI agents and Claude Code, and nothing reaches the server without passing your rules. This is the rule we recommend for review_code:

policy.json

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

review_code is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

Create a free account and register Claude Code — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Claude Code tools

Execute simulate_command Simulates the execution of a given command. Execute your_own_query Sends a custom query with context. Write fix_code Fixes bugs or issues in the given code. Write test_code Generates tests for the given code. Write edit_code Edits the given code based on instructions. Read explain_code Provides detailed explanation of the given code.

All 7 Claude Code tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about review_code

What does the review_code tool do? +

Reviews the given code. It is categorised as a Read tool in the Claude Code MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on review_code? +

Register the Claude Code MCP server in PolicyLayer and add a rule for review_code: 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 Claude Code. Nothing to install.

What risk level is review_code? +

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

Can I rate-limit review_code? +

Yes. Add a rate_limit block to the review_code 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 review_code completely? +

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

review_code is provided by the Claude Code MCP server (kunihiros/claude-code-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Claude Code tool call.

Start from Claude Code, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →