append_context_snapshot · State Trace MCP: Risk & Policy

WHAT IT DOES

What append_context_snapshot does on State Trace

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

WHY IT NEEDS A POLICY

Why append_context_snapshot needs a policy

The tool writes new context snapshot records associated with a run or task. This is a reversible write operation (appending data) with no indication of deletion or financial impact. Misuse could pollute working memory with incorrect context, affecting agent behavior, hence medium severity.

From the tool's definition 'Append an explicit context snapshot' — creates/adds new snapshot data for a run or task

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

append_context_snapshot Rate-limited

append_context_snapshot 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": {
    "append_context_snapshot": {
      "limits": [
        {
          "counter": "append_context_snapshot_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 State Trace, so you can run agents against it safely.

FAQ

Questions about append_context_snapshot

What does the append_context_snapshot tool do? +

Append an explicit context snapshot for a run or a task. It is categorised as a Write tool in the State Trace MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on append_context_snapshot? +

Register the State Trace MCP server in PolicyLayer and add a rule for append_context_snapshot: 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 State Trace. Nothing to install.

What risk level is append_context_snapshot? +

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

Can I rate-limit append_context_snapshot? +

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

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

append_context_snapshot is provided by the State Trace MCP server (agent-pattern-labs/state-trace). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.