chat_vision · MCP Vision Server MCP: Risk & Policy

WHAT IT DOES

What chat_vision does on MCP Vision Server

AI agents invoke chat_vision to trigger actions in MCP Vision 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 chat_vision needs a policy

The server description mentions multi-turn visual dialogues and session persistence, suggesting 'chat_vision' likely executes conversational/interactive image analysis sessions using an external OpenAI-compatible API. This involves triggering external operations (API calls), placing it in Execute. However, the empty description lowers confidence significantly.

From the tool's definition Tool name 'chat_vision' on a server described as supporting 'multi-turn visual dialogues' and 'session persistence'; description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

chat_vision Rate-limited

chat_vision 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": {
    "chat_vision": {
      "limits": [
        {
          "counter": "chat_vision_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 Vision Server, so you can run agents against it safely.

FAQ

Questions about chat_vision

What does the chat_vision tool do? +

chat_vision. It is categorised as a Execute tool in the MCP Vision 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 chat_vision? +

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

What risk level is chat_vision? +

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

Can I rate-limit chat_vision? +

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

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

chat_vision is provided by the MCP Vision Server MCP server (lzmw/mcp-vision-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.