import_png · PostGIS Yukon MCP: Risk & Policy

WHAT IT DOES

What import_png does on PostGIS Yukon MCP

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

WHY IT NEEDS A POLICY

Why import_png needs a policy

An AI agent can call import_png faster than any human can review — one bad instruction and it creates or modifies resources in PostGIS Yukon MCP by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

import_png Rate-limited

import_png 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": {
    "import_png": {
      "limits": [
        {
          "counter": "import_png_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 PostGIS Yukon MCP, so you can run agents against it safely.

FAQ

Questions about import_png

What does the import_png tool do? +

导入 PNG 图像作为地理配准栅格. It is categorised as a Write tool in the PostGIS Yukon MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on import_png? +

Register the PostGIS Yukon MCP server in PolicyLayer and add a rule for import_png: 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 PostGIS Yukon MCP. Nothing to install.

What risk level is import_png? +

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

Can I rate-limit import_png? +

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

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

import_png is provided by the PostGIS Yukon MCP server (zmgiser/postgis_yukon_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.