The External Memory Prompt

Design a file-based working memory for an agent.

Agent purpose: [DESCRIBE]
Environment: [DOES IT HAVE FILESYSTEM ACCESS? WHAT SCOPE?]
Run length: [DESCRIBE]

Produce:
1. Directory structure and naming conventions
2. What the agent writes and when
3. File formats — what structure makes each file useful when
   re-read
4. How the agent finds what it wrote earlier
5. Instructions for the system prompt telling the agent to use this
6. Cleanup: what is removed and when
7. What must never be written to disk

Then produce the system prompt section instructing the agent to use
it. It should cover:
- When to write (after finding something worth remembering, not
  continuously)
- What a good note contains
- To check existing notes before starting related work
- To update rather than duplicate
- To delete notes that turn out to be wrong

This is often the highest-leverage change for long-running agents:
a plain markdown file the agent maintains outperforms elaborate
memory infrastructure for most workloads.