write_bdf · pyNastran MCP Server MCP: Risk & Policy

WHAT IT DOES

What write_bdf does on pyNastran MCP Server

AI agents use write_bdf to create or update resources in pyNastran MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your pyNastran MCP Server environment.

WHY IT NEEDS A POLICY

Why write_bdf needs a policy

This tool creates new files containing Nastran Finite Element Analysis models. While reversible (files can be deleted or overwritten), unauthorized or erroneous writes could overwrite existing critical engineering models, corrupt project structures, or cause loss of work.

From the tool's definition Tool name 'write_bdf' and description 'Write BDF model to a new file' explicitly indicate the tool creates or modifies data by writing Nastran BDF files to the filesystem.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

write_bdf Rate-limited

write_bdf stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "write_bdf": {
      "limits": [
        {
          "counter": "write_bdf_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about write_bdf

What does the write_bdf tool do? +

Write BDF model to a new file. It is categorised as a Write tool in the pyNastran MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on write_bdf? +

Register the pyNastran MCP Server MCP server in PolicyLayer and add a rule for write_bdf: 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 pyNastran MCP Server. Nothing to install.

What risk level is write_bdf? +

write_bdf is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit write_bdf? +

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

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

write_bdf is provided by the pyNastran MCP Server MCP server (shaoqigit/pynastran-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.