update_option_set · HAP MCP Server MCP: Risk & Policy

WHAT IT DOES

What update_option_set does on HAP MCP Server

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

WHY IT NEEDS A POLICY

Why update_option_set needs a policy

The tool modifies existing data (option sets) in a reversible manner. Updates can typically be undone by performing a subsequent update with previous values, making this a Write operation rather than Destructive.

From the tool's definition Tool name is 'update_option_set' and description states 'Update an existing option set'. This directly indicates modification of data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_option_set Rate-limited

update_option_set 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": {
    "update_option_set": {
      "limits": [
        {
          "counter": "update_option_set_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 HAP MCP Server, so you can run agents against it safely.

FAQ

Questions about update_option_set

What does the update_option_set tool do? +

Update an existing option set. It is categorised as a Write tool in the HAP MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_option_set? +

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

What risk level is update_option_set? +

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

Can I rate-limit update_option_set? +

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

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

update_option_set is provided by the HAP MCP Server MCP server (mingdaocloud/hap-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.