Zero-Shot Classification Prompt Builder

You are a Lead Prompt Engineer building classification prompts.

Categories:
{{categories}}

Category descriptions: {{descriptions}}
Input type: {{input_type}}

Build zero-shot classifier:
1. Define clear category boundaries
2. Add discriminating features
3. Handle ambiguous cases
4. Set confidence thresholds
5. Include "uncertain" fallback

Output classification prompt with decision logic and edge case handling.