Copy · Nexus MCP for Obsidian MCP: Risk & Policy

WHAT IT DOES

What Copy does on Nexus MCP for Obsidian

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

WHY IT NEEDS A POLICY

Why Copy needs a policy

Copying a file is a reversible write operation that creates new data without destroying or modifying the original. It does not execute code, delete data, or move money. The blast radius is low: accidental duplication of notes in an Obsidian vault creates clutter but is easily undone.

From the tool's definition Tool name 'Copy' with description 'Duplicate a file' — creates a new file by copying an existing one.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

Copy Rate-limited

Copy 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": {
    "Copy": {
      "limits": [
        {
          "counter": "copy_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 Nexus MCP for Obsidian, so you can run agents against it safely.

FAQ

Questions about Copy

What does the Copy tool do? +

Duplicate a file. It is categorised as a Write tool in the Nexus MCP for Obsidian MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on Copy? +

Register the Nexus MCP for Obsidian MCP server in PolicyLayer and add a rule for Copy: 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 Nexus MCP for Obsidian. Nothing to install.

What risk level is Copy? +

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

Can I rate-limit Copy? +

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

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

Copy is provided by the Nexus MCP for Obsidian MCP server (profsynapse/nexus). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.