Build a Control Flow Graph (CFG) for a function/method: if/else branches, loops, try/catch, returns, throws. Shows logical paths through the code. Outputs Mermaid diagram, ASCII, or JSON. Use to understand branching logic before modifying complex functions. For call-level graph (who calls whom) u...
AI agents call get_control_flow to retrieve information from Trace without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and analyzes code structure to generate control flow visualizations. It performs no modifications, deletions, or execution of code. The explicit 'Read-only' designation confirms it is a safe information retrieval operation. Severity is low because misuse by an AI agent would merely produce incorrect analysis diagrams without affecting actual code or systems.
From the tool's definition Tool description explicitly states 'Read-only' and describes visualization capabilities: 'Outputs Mermaid diagram, ASCII, or JSON'.
Documented attack patterns abuse exactly the kind of access get_control_flow gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Trace, and nothing reaches the server without passing your rules. This is the rule we recommend for get_control_flow:
{
"version": "1",
"default": "deny",
"tools": {
"get_control_flow": {}
}
}get_control_flow is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Build a Control Flow Graph (CFG) for a function/method: if/else branches, loops, try/catch, returns, throws. Shows logical paths through the code. Outputs Mermaid diagram, ASCII, or JSON. Use to understand branching logic before modifying complex functions. For call-level graph (who calls whom) use get_call_graph instead. Read-only. Returns Mermaid/ASCII/JSON: { nodes, edges, entryPoint, exitPoints }. It is categorised as a Read tool in the Trace MCP Server, which means it retrieves data without modifying state.
Register the Trace MCP server in PolicyLayer and add a rule for get_control_flow: 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 Trace. Nothing to install.
get_control_flow 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 get_control_flow 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 get_control_flow. 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.
get_control_flow is provided by the Trace MCP server (nikolai-vysotskyi/trace-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 178 Trace tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
178 Trace tools catalogued and risk-classified — across an index of 42,500+ MCP servers.