Prompt Optimization Skill

Overview

Automatically applies prompt repetition for Haiku agents to improve accuracy by 4-5x on structured tasks.

Research Source: "Prompt Repetition Improves Non-Reasoning LLMs" (arXiv 2512.14982v1)

When to Activate

This skill activates automatically for:

• Haiku agents executing structured tasks
• Unit test execution
• Linting and formatting
• Parsing and extraction
• List operations (find, filter, count)

How It Works

BEFORE:
prompt = "Run unit tests in tests/ directory"

AFTER (with skill):
prompt = "Run unit tests in tests/ directory\n\nRun unit tests in tests/ directory"

The repeated prompt enables bidirectional attention within the parallelizable prefill stage, improving accuracy without latency penalty.

Performance Impact

Latency: Zero impact (occurs in prefill, not generation)

Configuration

Enable/Disable

# Enabled by default for Haiku agents
LOKI_PROMPT_REPETITION=true

# Disable if needed
LOKI_PROMPT_REPETITION=false

Repetition Count

# 2x repetition (default)
LOKI_PROMPT_REPETITION_COUNT=2

# 3x repetition (for position-critical tasks)
LOKI_PROMPT_REPETITION_COUNT=3

Agent Instructions

When you are a Haiku agent and the task involves:

• Running tests
• Executing linters
• Parsing structured data
• Finding items in lists
• Counting or filtering

Your prompt will be automatically repeated 2x to improve accuracy. No action needed from you.

If you are an Opus or Sonnet agent, this skill does NOT apply (reasoning models see no benefit from repetition).

Metrics

Track prompt optimization impact:

.loki/metrics/prompt-optimization/
├── accuracy-improvement.json
└── cost-benefit.json

References

See references/prompt-repetition.md for full documentation.

Version: 1.0.0