vim_visual · Mcp Neovim Server MCP: Risk & Policy

WHAT IT DOES

What vim_visual does on Mcp Neovim Server

AI agents invoke vim_visual to trigger actions in Mcp Neovim Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why vim_visual needs a policy

Creating visual selections in a Neovim buffer is an interactive editor action that triggers state changes in the running editor process. While selecting text alone is relatively benign, visual mode selections in Neovim can be chained with subsequent commands (delete, yank, replace, etc.), and this tool interacts with an external running process. It goes beyond a simple read, qualifying as Execute.

From the tool's definition Create visual mode selections in the buffer

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vim_visual Rate-limited

vim_visual stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "vim_visual": {
      "limits": [
        {
          "counter": "vim_visual_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about vim_visual

What does the vim_visual tool do? +

Create visual mode selections in the buffer. It is categorised as a Execute tool in the Mcp Neovim Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on vim_visual? +

Register the Mcp Neovim Server MCP server in PolicyLayer and add a rule for vim_visual: 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 Neovim Server. Nothing to install.

What risk level is vim_visual? +

vim_visual is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit vim_visual? +

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

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

vim_visual is provided by the Mcp Neovim Server MCP server (mcp-neovim-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.