journal_append · Kontexta MCP: Risk & Policy

WHAT IT DOES

What journal_append does on Kontexta

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

WHY IT NEEDS A POLICY

Why journal_append needs a policy

The tool appends data to a journal file, which is a reversible write operation. It creates/modifies a daily journal entry with a timestamp. No execution, deletion, or financial implications. Severity is low as it only adds text to a log-like file.

From the tool's definition Append a timestamped text entry to today

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

journal_append Rate-limited

journal_append 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": {
    "journal_append": {
      "limits": [
        {
          "counter": "journal_append_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 Kontexta, so you can run agents against it safely.

FAQ

Questions about journal_append

What does the journal_append tool do? +

Append a timestamped text entry to today. It is categorised as a Write tool in the Kontexta MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on journal_append? +

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

What risk level is journal_append? +

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

Can I rate-limit journal_append? +

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

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

journal_append is provided by the Kontexta MCP server (safiyu/kontexta). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.