When your island has performance problems, you can work through them with an AI agent connected through the UEFN MCP. You describe the problem and decide where to focus. The agent runs the profiling tools, explains what it finds, and suggests fixes. You can review each fix before it’s applied in the editor.
You don’t need to know the profiling tools in depth. The agent handles the mechanics, and you guide the investigation. This page covers the general workflow for two common problems, frame drops and high memory use. It also lists questions you can ask to steer the agent.
To see this workflow on an example island, watch UEFN Profiling: Resolving Performance Issues with the MCP.
This page assumes you've already connected an AI agent to UEFN. If you haven't, start with UEFN MCP.
AI agents don't always take the same steps, so your results can look different from the video and the examples on this page. Results depend on the agent, the model version, and how you word your prompts.
Before You Begin
You need the following:
An AI agent connected to your UEFN project. See UEFN MCP.
A play session of your island that's running. You can start it yourself, or ask the agent to start it.
Knowing the profiling tools helps you follow and check the agent's results. See Spatial Profiler, Timing Insights in UEFN, and Memory Snapshot.
Key Terms
These terms come up when you work with the agent:
Term | What it means |
Profiling | Measuring how your island performs to find areas to improve to make it perform better. |
Frame drops | When the game can't draw new frames fast enough, so movement looks choppy or stutters. |
Frame time | How long the game takes to draw one frame, in milliseconds. Lower is better. |
Budget | The limit your island should stay under to run smoothly, such as the time allowed per frame or the amount of memory it can use. |
Memory | The space on the player's device that holds your island's assets while they play. Using too much can cause problems on devices with less memory, such as phones. |
How the Agent Profiles Your Island
The agent uses the same profiling tools that are built into UEFN:
Tool | What the agent uses it for |
Checking measurements like frame time and memory, and whether they're over budget. And where they happen in your map. | |
Finding what's taking the most time in each frame, either on the client or server. | |
Tracking down assets contributing to performance issues or high memory use. |
After the agent makes a fix, it can measure again and compare the results with a previous measurement, so it can see whether the fix worked.
Fix Frame Drops
This is an example workflow when your island stutters during play or the editor shows a performance warning.
With the play session running, describe the problem to the agent. For example:
Command LineMy island has frame drops. Can you take a look?The agent measures your island and reports what it finds. The report can include:
What's causing the frame drops, such as a specific function, event or system.
How far over budget your island is, such as how long each frame takes compared to the time allowed.
Why the cause is slowing the game down.
Review the agents report.
Before you approve a fix, ask the agent to explain what it found and what it would change. Because the agent is connected to UEFN, it can also explain how features work and suggest best practices. For example:
Command LineWhy is this slowing down my island? What would you change to fix it?When you approve of the plan, ask the agent to make the changes.
The agent edits the assets in the editor. It can then measure your island again and compare the results with the first measurement.
Play the session, or ask the agent to do it, to check that the stutter is gone.
Fix High Memory Use
This is an example workflow when the agent or the editor reports that your island is over its memory budget. This matters most if you want your island to play smoothly on phones and other devices with less memory.
Ask the agent how to fix it. For example:
Command LineMy island is using a lot of memory. How can we fix this?The agent may take a Memory Snapshot, which lists the assets using the most memory, and recommends changes.
Ask the agent to explain any recommendation you're not sure about. When you're ready to continue, ask the agent to approve the changes.
The agent makes the changes, sends them to the running play session, and takes another Memory Snapshot to confirm memory is improved.
Questions to Ask the Agent
You can use your own words. These examples are a starting point.
Results can vary by AI agent.
Goal | Example questions |
Find the problem | My island has frame drops. Can you take a look? Is my island over any performance budgets? |
Understand the problem | Why is this slowing down my island? What would you change to fix it, and why? |
Fix the problem | Make the changes you recommended, then measure again and compare the results. |
Check memory | Take a memory snapshot and tell me which assets use the most memory. |
Learn about a tool | Can you explain how to read my Timing Insights results, and what kinds of problems it helps find? |
Tips for Profiling With the MCP
Working With the Agent
Keep the play session running. The agent needs your island to be running to measure it.
Ask before you approve. Ask the agent to explain what it found and what it plans to change before it changes anything.
Ask it to measure again after a fix. Comparing before and after shows whether the fix worked.
Double-check results that look wrong. The agent's work can sometimes make the editor slow down or freeze for a moment, which can affect its measurements. To check a result, open the profiling tool yourself. See Known Issues in UEFN MCP.
For general tips on asking the agent for help, see Tips for Best Results in UEFN MCP.
Review Changes the Agent Makes
The changes the agent makes are regular edits in the editor, the same as changes you make by hand. You can open the affected assets to review or undo them at any time.
