harvest_stop_timer

THE RISK

Medium Risk

Why harvest_stop_timer needs a policy

Stopping a timer modifies the state of an existing time entry (sets the end time) but does not delete or irreversibly destroy data. It is a reversible write operation — the timer could potentially be restarted. Blast radius is low as it only affects a single time entry's running state.

From the tool's definition Stop a running timer on a time entry

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

POLICY

How to control harvest_stop_timer

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

policy.json

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

harvest_stop_timer 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 Harvest MCP Server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

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EXPLORE

Related tools and policies

More Harvest MCP Server tools

Destructive harvest_delete_time_entry Delete a time entry. Use this to remove erroneous or unwanted time entries. Write harvest_create_time_entry Create a new time entry Read harvest_compute_budget_performance Analyze employee performance based on budget adherence per project. Compares actual hours Read harvest_aggregate_time Aggregate time entries by various dimensions. Simple convenience tool for getting total ho Read harvest_compute_profitability Compute profitability metrics for a date range. Supports three modes: time_based (hours r Read harvest_compute_utilization Compute utilization metrics for a date range. Shows how much of available capacity is bein Read harvest_get_company Get information about the authenticated Harvest company/account Read harvest_get_current_user Get information about the currently authenticated Harvest user

All 21 Harvest MCP Server 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 harvest_stop_timer

What does the harvest_stop_timer tool do? +

Stop a running timer on a time entry. It is categorised as a Write tool in the Harvest 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 harvest_stop_timer? +

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

What risk level is harvest_stop_timer? +

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

Can I rate-limit harvest_stop_timer? +

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

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

harvest_stop_timer is provided by the Harvest MCP Server MCP server (southleft/harvest-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Harvest MCP Server tool call.

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

CHECK YOUR STACK →