terminal-resize · TermSSH MCP: Risk & Policy

WHAT IT DOES

What terminal-resize does on TermSSH MCP

AI agents invoke terminal-resize to trigger actions in TermSSH MCP. 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 terminal-resize needs a policy

Resizing a terminal session is an operational action that affects an active remote session's dimensions. It doesn't read data, write files, or destroy anything, but it does interact with and alter the state of a live execution environment (an SSH terminal session). The blast radius is low since resizing alone doesn't cause data loss or financial impact, but it is part of a remote execution context.

From the tool's definition 'Resize an existing interactive terminal session' — modifies the state of a running terminal session on a remote SSH connection

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

terminal-resize Rate-limited

terminal-resize 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": {
    "terminal-resize": {
      "limits": [
        {
          "counter": "terminal-resize_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 TermSSH MCP, so you can run agents against it safely.

FAQ

Questions about terminal-resize

What does the terminal-resize tool do? +

Resize an existing interactive terminal session. It is categorised as a Execute tool in the TermSSH MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on terminal-resize? +

Register the TermSSH MCP server in PolicyLayer and add a rule for terminal-resize: 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 TermSSH MCP. Nothing to install.

What risk level is terminal-resize? +

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

Can I rate-limit terminal-resize? +

Yes. Add a rate_limit block to the terminal-resize 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 terminal-resize completely? +

Set action: deny in the PolicyLayer policy for terminal-resize. 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 terminal-resize? +

terminal-resize is provided by the TermSSH MCP server (rayss868/termssh-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.