Improve a prompt that half-works

Here is a prompt that gives me inconsistent results:

{{prompt}}

What I actually want: {{intent}}

Tell me which parts are ambiguous and why each one lets the model drift — be
specific about the failure, not general about clarity. Then rewrite it.

Keep the rewrite as short as the job allows. Do not pad it with role-play,
politeness, or threats about accuracy.

What to fill in

{{prompt}}

Your prompt — e.g. Paste the prompt that misbehaves

{{intent}}

What you actually want — e.g. a one-paragraph summary, no bullets

What it produces

Two sources of drift:

1. "Summarise this" does not say how long, so length varies
   run to run. Name the length.
2. Nothing forbids bullets, and bullets are the default shape
   for anything list-like. Say "prose, no bullets".

Rewritten: Summarise the text below in one paragraph of at
most 80 words. Prose only — no bullets, no headings.