What problem does it solve?
Agent Harness Construction helps designers improve how an AI agent plans, calls tools, recovers from errors, and converges on completion, increasing reliability and success rates.
Core Features & Use Cases
- Action Space Design: Use stable, explicit tool names; inputs schema-first and narrow; return deterministic output shapes.
- Granularity Rules: Use micro-tools for high-risk operations; use medium tools for common edit/read/search loops; use macro-tools only when round-trip overhead is the dominant cost.
- Observation Design: Each tool response should include:
status: success|warning|error
summary: one-line result
next_actions: actionable follow-ups
artifacts: file paths / IDs
- Error Recovery Contract: For every error path, include root cause hint, safe retry instruction, explicit stop condition.
- Context Budgeting: Keep system prompt minimal and invariant; move large guidance into skills loaded on demand; prefer references to files over inlining long documents; compact at phase boundaries.
- Architecture Pattern Guidance: ReAct: best for exploratory tasks with uncertain path; Function-calling: best for structured deterministic flows; Hybrid (recommended): ReAct planning + typed tool execution.
- Benchmarking: Track completion rate, retries per task, pass@1 and pass@3, cost per successful task
- Anti-Patterns: Too many tools with overlapping semantics; Opaque tool output with no recovery hints; Error-only output without next steps; Context overloading with irrelevant references.
Quick Start
Propose a redesigned action space, explicit tool definitions, and observation formatting to improve an agent’s completion rate on a given task.