spike_synthesize · Hedgehog MCP: Risk & Policy

WHAT IT DOES

What spike_synthesize does on Hedgehog

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

WHY IT NEEDS A POLICY

Why spike_synthesize needs a policy

The tool creates a new synthesis document by aggregating and comparing data from existing exploration branches. This is a write operation that generates new content reversibly (the document can be modified or deleted). It does not execute arbitrary code, delete data irreversibly, or involve financial transactions.

From the tool's definition Tool name 'spike_synthesize' and description 'Create synthesis document comparing all explored branches' indicate document creation/generation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

spike_synthesize Rate-limited

spike_synthesize 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": {
    "spike_synthesize": {
      "limits": [
        {
          "counter": "spike_synthesize_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 Hedgehog, so you can run agents against it safely.

FAQ

Questions about spike_synthesize

What does the spike_synthesize tool do? +

Create synthesis document comparing all explored branches. It is categorised as a Write tool in the Hedgehog MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on spike_synthesize? +

Register the Hedgehog MCP server in PolicyLayer and add a rule for spike_synthesize: 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 Hedgehog. Nothing to install.

What risk level is spike_synthesize? +

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

Can I rate-limit spike_synthesize? +

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

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

spike_synthesize is provided by the Hedgehog MCP server (jpalmerr/hedgehog). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.