Agent Testing Framework

5-Layer Testing Approach

Layer 1: Output Quality (Unit-Level)

Validate agent produces correct, well-structured outputs for typical inputs.

Test: Agent follows workflow phases | Outputs match expected format/structure | Domain-specific rules correctly applied | Token efficiency within bounds

How: Manual invocation with representative inputs. Check against acceptance criteria in agent description.

Layer 2: Integration / Handoff Validation

Validate correct input/output between agents in workflows.

Test: Input parsing handles upstream format | Output format matches downstream expectations | Error signals propagate correctly | Subagent mode activation works (skip greet, execute autonomously)

How: End-to-end workflow execution through full agent chain (e.g., DISCUSS -> DESIGN -> DELIVER).

Layer 3: Adversarial Output Validation

Challenge validity of agent outputs rather than accepting at face value.

Test: Source verification (cited sources real and accurate?) | Bias detection (favors one approach without evidence?) | Edge case coverage | Completeness (required sections present?)

How: Peer review by -reviewer agent using structured critique dimensions.

Layer 4: Adversarial Verification (Peer Review)

Independent review to catch biases and blind spots in agent design.

Test: Definition follows validation checklist? | Redundant Claude default instructions? | Over/under-specified? | Could simpler agent achieve same results?

How: @nw-agent-builder validates via 11-point checklist or @agent-builder-reviewer runs structured review.

Layer 5: Security Validation

Test resilience against misuse and prompt injection.

Test: Tool restriction enforcement | maxTurns respected | Permission mode correctly scoped | Agent stays within declared scope

How: Frontmatter fields enforce at platform level. Verify configuration.

Prompt Injection Resistance

Claude Code platform provides injection resistance through: subagent isolation (own context, no sub-subagents) | Tool restriction via frontmatter tools | Permission modes via permissionMode | Hook-based validation (PreToolUse, PostToolUse)

Do NOT add prose-based injection defense. Configure platform features:

yaml
---
tools: Read, Glob, Grep           # Only tools this agent needs
maxTurns: 30                       # Prevents runaway execution
permissionMode: default            # User approves dangerous actions
---

Security Validation Checklist

• ] tools restricted to minimum necessary (least privilege)
• ] maxTurns set to prevent runaway execution
• ] permissionMode appropriate for risk level
• ] No Bash unless agent requires command execution
• ] No Write unless agent creates/modifies files
• ] Description accurately describes scope
• ] Subagent mode handles autonomous execution correctly
• ] No sensitive data hardcoded in definition

Testing Workflow for New Agents

1. Create with minimal definition
2. Layer 1: Invoke with 2-3 representative inputs, check outputs
3. Layer 2: Run in workflow chain if applicable
4. Fix failures observed
5. Validate: Run 11-point checklist
6. Iterate: Add instructions only for observed failure modes