fem_read_results · FreeCAD MCP: Risk & Policy

WHAT IT DOES

What fem_read_results does on FreeCAD MCP

AI agents call fem_read_results to retrieve information from FreeCAD MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

WHY IT NEEDS A POLICY

Why fem_read_results needs a policy

The 'read' prefix strongly suggests this tool retrieves or queries existing FEM analysis results (stress, displacement, temperature data, etc.) from completed structural/fluid simulations.

From the tool's definition Tool name 'fem_read_results' contains 'read', indicating data retrieval without modification. FEM (Finite Element Method) analysis results are inherently output-only artifacts from prior simulations.

Attacks that exploit this kind of access

Questions about fem_read_results

What does the fem_read_results tool do? +

fem_read_results. It is categorised as a Read tool in the FreeCAD MCP MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on fem_read_results? +

Register the FreeCAD MCP server in PolicyLayer and add a rule for fem_read_results: 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 FreeCAD MCP. Nothing to install.

What risk level is fem_read_results? +

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

Can I rate-limit fem_read_results? +

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

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

fem_read_results is provided by the FreeCAD MCP server (sandraschi/freecad-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.