create_journal_entry

THE RISK

Medium Risk

Why create_journal_entry needs a policy

This tool creates new data (journal entries) in a Day One journal, which is a reversible modification. While journal entries might contain personal information and their creation could be misused for impersonation or spam, the action is not destructive (entries can be edited or deleted later), not financially consequential, and not code execution.

From the tool's definition Tool name is 'create_journal_entry' and description states 'Create a new entry in Day One journal with support for attachments, location, and metadata'. The verb 'Create' and the action of adding a new journal entry are characteristic of Write operations.

Documented attack patterns abuse exactly the kind of access create_journal_entry gives an agent:

POLICY

How to control create_journal_entry

PolicyLayer is an MCP gateway — it sits between your AI agents and MCP-DayOne, and nothing reaches the server without passing your rules. This is the rule we recommend for create_journal_entry:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_journal_entry": {
      "limits": [
        {
          "counter": "create_journal_entry_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

create_journal_entry 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.

Create a free account and register MCP-DayOne — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More MCP-DayOne tools

Write create_entry_with_attachments Create a journal entry with file attachments (photos, videos, audio, PDFs) Write create_location_entry Create a journal entry with location coordinates Read get_entries_by_date Get journal entries for a specific date across multiple years ( Read get_entry_count Get the total number of entries in a journal Read get_entry_count_from_db Get actual entry count from Day One database Read list_journals List all available Day One journals Read list_journals_from_db List all journals from database with entry counts Read read_recent_entries Read recent journal entries from Day One database

All 10 MCP-DayOne tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about create_journal_entry

What does the create_journal_entry tool do? +

Create a new entry in Day One journal with support for attachments, location, and metadata. It is categorised as a Write tool in the MCP-DayOne MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_journal_entry? +

Register the MCP-DayOne MCP server in PolicyLayer and add a rule for create_journal_entry: 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 MCP-DayOne. Nothing to install.

What risk level is create_journal_entry? +

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

Can I rate-limit create_journal_entry? +

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

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

create_journal_entry is provided by the MCP-DayOne MCP server (quevin/mcp-dayone). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every MCP-DayOne tool call.

Start from MCP-DayOne, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →