block_update_exceptions · AF_ MCP: Risk & Policy

WHAT IT DOES

What block_update_exceptions does on AF_MCP

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

WHY IT NEEDS A POLICY

Why block_update_exceptions needs a policy

This tool modifies (updates) exception configurations for device blocking rules in AF security devices. While it changes security device state, the modification is reversible through other tools (like apply_blacklist_unblock or subsequent updates), making it Write rather than Destructive.

From the tool's definition Tool name 'block_update_exceptions' and description '批量修改例外封锁配置' (bulk modify exception blocking configuration) indicate modification of device blocking rules and exceptions.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

block_update_exceptions Rate-limited

block_update_exceptions 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": {
    "block_update_exceptions": {
      "limits": [
        {
          "counter": "block_update_exceptions_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 AF_MCP, so you can run agents against it safely.

FAQ

Questions about block_update_exceptions

What does the block_update_exceptions tool do? +

批量修改例外封锁配置。. It is categorised as a Write tool in the AF_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 block_update_exceptions? +

Register the AF_ MCP server in PolicyLayer and add a rule for block_update_exceptions: 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 AF_MCP. Nothing to install.

What risk level is block_update_exceptions? +

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

Can I rate-limit block_update_exceptions? +

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

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

block_update_exceptions is provided by the AF_ MCP server (xiaqijun/af_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.