Keeping Prompts Maintainable

Unit ID: PAW-M06-U04 Estimated active time: 20-25 minutes

Prompts accumulate

A prompt that works gets reused. Each time something goes slightly wrong, a line is added.

After a few months it is 40 lines long, nobody remembers why half of them are there, and removing any of them feels risky.

This is the same problem as any other document that grows by patching.

Give every rule a reason

The single most useful maintenance habit is a short note on why each unusual rule exists.

CONSTRAINTS
- under 200 words
- no figures beyond the four supplied
    (added after an invented completion rate reached a board pack, March)
- do not mention pricing
    (pricing is owned by another team)
- keep the caveat sentence exactly as written
    (agreed wording with legal)

Now a later reader can tell which lines are safe to change.

Date and version them

PROMPT: monthly course summary
Version: 3
Updated: 2026-07-29
Changed:  added PRESERVE block after figures were rounded in v2
Owner:   (name)
Retire when: the reporting template changes

Six lines at the top of a saved prompt. The "retire when" line is the one that stops a library filling with prompts for work nobody does any more.

Split when a prompt does two jobs

If a prompt has two output sections that are used by different people at different times, it is two prompts.

Splitting them makes each shorter, easier to review, and separately improvable. Combined prompts are usually the result of avoiding a second copy-paste, which is a poor trade.

Review the library, not just the prompt

Once you have more than about ten saved prompts, schedule a look through them — quarterly is enough.

Delete what is unused, merge near-duplicates, and check that anything with a "retire when" condition has not met it.

Mini practice

Take your longest saved prompt.

Add a reason note to every rule you cannot immediately justify, and delete any rule where you cannot construct one.

Then add the six-line header.

Mark complete