AI agents call dap_locals to retrieve information from Mcp Debugpy without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool only reads and returns local variable values from a debug stack frame. It has no side effects, does not modify state, and cannot execute code or alter data. It is a pure read/inspection operation within a debugger context.
From the tool's definition Return locals from the top (or last stopped) stack frame
Documented attack patterns abuse exactly the kind of access dap_locals gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Debugpy, and nothing reaches the server without passing your rules. This is the rule we recommend for dap_locals:
{
"version": "1",
"default": "deny",
"tools": {
"dap_locals": {}
}
} dap_locals is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Return locals from the top (or last stopped) stack frame. It is categorised as a Read tool in the Mcp Debugpy MCP Server, which means it retrieves data without modifying state.
Register the Mcp Debugpy MCP server in PolicyLayer and add a rule for dap_locals: 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 Mcp Debugpy. Nothing to install.
dap_locals is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the dap_locals 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.
Set action: deny in the PolicyLayer policy for dap_locals. 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.
dap_locals is provided by the Mcp Debugpy MCP server (markomanninen/mcp-debugpy). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Mcp Debugpy, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
16 Mcp Debugpy tools catalogued and risk-classified — across an index of 43,000+ MCP servers.