| name | agent-harness-construction |
| description | Framework for designing quality agents with proper action space and contracts |
| version | 0.1.0 |
| level | 3 |
| triggers | ["design an agent","agent quality framework","harness construction","agent architecture"] |
| context_files | ["context/project.md","context/decisions.md"] |
| steps | [{"name":"Define Action Space","description":"Specify granularity and tool allowlist"},{"name":"Establish Observation Contract","description":"Define required fields in tool responses"},{"name":"Design Recovery Contract","description":"Specify error handling and retry logic"},{"name":"Budget Context","description":"Calculate context costs and set limits"},{"name":"Select Architecture Pattern","description":"Choose ReAct, function-calling, or Hybrid"},{"name":"Define Success Metrics","description":"Track completion rate, retries, pass@k, cost per task"}] |
Agent Harness Construction Skill
Framework for designing quality agents. Defines contracts, budgets, and measurement before implementation.
What Claude Gets Wrong Without This Skill
Without systematic agent design, agents:
- Have unclear tool boundaries (too permissive or too restrictive)
- Return inconsistent response formats (breaks downstream parsing)
- Fail silently on errors (no recovery strategy)
- Consume unbounded context (budget overruns)
- Lack measurable success criteria (can't tell if agent is improving)
Agent harness construction ensures agents are well-specified before deployment.
Four Quality Dimensions
1. Action Space
Defines: What tools can this agent use? At what granularity?
Granularity: Micro (single file/command, high-risk), Medium (edit/read loops, standard dev), Macro (Task/orchestration, complex workflows).
Tool Allowlist Pattern:
tools:
- Read
- Grep
- Glob
disallowedTools:
- Write
- Edit
- Bash
Rule: Start restrictive, expand only when justified. Removing permissions later breaks existing workflows.
2. Observation Contract
Defines: What fields must every tool response include?
Required Fields:
status: SUCCESS | PARTIAL | FAILUREsummary: One-line description of what happenednext_actions: Array of suggested follow-upsartifacts: Paths to files created/modified
Why: Enables reliable parsing, orchestrator coordination, and chaining without re-planning. Anti-pattern: raw output with no structure.
3. Recovery Contract
Defines: How does agent handle errors?
Strategies: Retry with backoff (transient errors, max 3), escalate to human (ambiguous/security, max 2 auto-attempts), graceful degradation (optional features unavailable), circuit breaker (3 identical failures = stop).
