harness-engineering

# Harness Engineering Harness engineering designs the control system around an agent: what it may edit, how it receives feedback, where it writes state, how failures recover, and who can approve irreversible actions. The harness is the difference between a helpful agent session and an autonomous loop that can run for days without corrupting its objective. ## When to Activate Activate this skill when: - Building autonomous research or experimentation loops - Designing an agent environment with locked metrics and editable code or content - Creating PR-producing or background agents - Evaluating whether an agent can safely run without frequent human prompts - Adding novelty, ablation, pruning, rollback, or durable logging to an agent workflow - Preventing agents from gaming benchmarks, weakening rubrics, or losing state across compaction Do not activate this skill for adjacent work owned by other skills: - General quality gates, regression suites, or outcome metrics without autonomous control surfaces: `evaluation`. - Tool schemas, response formats, and recovery errors for harness tools: `tool-design`. - Project-level task-model fit, pipeline shape, and cost planning: `project-development`. - Remote sandbox, warm-pool, and hosted session infrastructure: `hosted-agents`. ## Core Concepts ### Harness Boundary Separate the agent from the environment it operates inside. The agent proposes actions; the harness defines allowed surfaces, feedback, persistence, and promotion rul...