get_derived_classes

THE RISK

Low Risk

Why get_derived_classes needs a policy

This tool performs static analysis to retrieve class hierarchy information from a C++ codebase. It is purely informational—it queries existing metadata about inheritance relationships without creating, modifying, executing code, or causing side effects. This aligns with the Read category (retrieves or queries data; no side effects).

From the tool's definition Tool name 'get_derived_classes' and description 'Get all classes that inherit from a given base class' indicate a retrieval operation that queries semantic information about code structure without modifying, executing, or deleting any data.

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

POLICY

How to control get_derived_classes

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

policy.json

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

get_derived_classes 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 C++ MCP Server — 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 →

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EXPLORE

Related tools and policies

More C++ MCP Server tools

Execute refresh_project Manually refresh/re-parse project files to detect changes Write set_project_directory Set the project directory to analyze (use this first before other commands) Read find_callees Find all functions called by a specific function Read find_callers Find all functions that call a specific function Read find_in_file Search for symbols within a specific file Read get_call_path Find call paths from one function to another Read get_class_hierarchy Get complete inheritance hierarchy for a C++ class Read get_class_info Get detailed information about a specific class

All 14 C++ MCP Server 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 get_derived_classes

What does the get_derived_classes tool do? +

Get all classes that inherit from a given base class. It is categorised as a Read tool in the C++ MCP Server MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on get_derived_classes? +

Register the C++ MCP Server MCP server in PolicyLayer and add a rule for get_derived_classes: 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 C++ MCP Server. Nothing to install.

What risk level is get_derived_classes? +

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

Can I rate-limit get_derived_classes? +

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

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

get_derived_classes is provided by the C++ MCP Server MCP server (kandrwmrtn/cplusplus_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every C++ MCP Server tool call.

Start from C++ MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →