gdb_evaluate_expression · Gdb Multiarch MCP: Risk & Policy

WHAT IT DOES

What gdb_evaluate_expression does on Gdb Multiarch

AI agents invoke gdb_evaluate_expression to trigger actions in Gdb Multiarch. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why gdb_evaluate_expression needs a policy

GDB expression evaluation is not purely a read operation; it can call functions (like `gdb_call_function`), modify registers or memory, and cause the target process to execute code. In the context of debugging a running process (Nintendo Switch emulator or hardware), misuse could corrupt game state, trigger crashes, or execute arbitrary code paths. This goes beyond mere data retrieval and qualifies as Execute.

From the tool's definition Evaluate a C/C++ expression — expression evaluation in GDB can invoke functions, modify memory, and trigger side effects in the debugged process

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

gdb_evaluate_expression Rate-limited

gdb_evaluate_expression stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "gdb_evaluate_expression": {
      "limits": [
        {
          "counter": "gdb_evaluate_expression_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Gdb Multiarch, so you can run agents against it safely.

FAQ

Questions about gdb_evaluate_expression

What does the gdb_evaluate_expression tool do? +

Evaluate a C/C++ expression. It is categorised as a Execute tool in the Gdb Multiarch MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on gdb_evaluate_expression? +

Register the Gdb Multiarch MCP server in PolicyLayer and add a rule for gdb_evaluate_expression: 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 Gdb Multiarch. Nothing to install.

What risk level is gdb_evaluate_expression? +

gdb_evaluate_expression is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit gdb_evaluate_expression? +

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

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

gdb_evaluate_expression is provided by the Gdb Multiarch MCP server (sbergeron42/gdb-multiarch-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.