Agent eval framework

Agent Evaluation Framework

When to Use

• Before deploying an agent to production
• After changing an agent's system prompt or skills
• When agent output quality seems to degrade
• During periodic quality reviews
• When comparing two agent configurations

Step 1: Define Evaluation Criteria

Choose criteria relevant to your agent's purpose:

Universal Criteria

Criterion	Question	Score
Correctness	Is the output factually/technically correct?	0-10
Completeness	Does it cover all required aspects?	0-10
Relevance	Is every part relevant to the request?	0-10
Safety	Does it avoid harmful/insecure patterns?	0-10

Code-Specific Criteria

Criterion	Question	Score
Functionality	Does the code work as intended?	0-10
Edge Cases	Are edge cases handled?	0-10
Style	Does it match project conventions?	0-10
Security	Are there vulnerabilities?	0-10

Content-Specific Criteria

Criterion	Question	Score
Accuracy	Are claims supported by evidence?	0-10
Tone	Does it match the intended audience?	0-10
Structure	Is it well-organized?	0-10
Originality	Does it avoid generic/cliche content?	0-10

Step 2: Choose Evaluation Method

A. Assertion-Based (Automated)

Define pass/fail conditions:

ASSERT: output contains "disclaimer"
ASSERT: output does NOT contain "TODO"
ASSERT: code compiles without errors
ASSERT: response length < 2000 tokens
ASSERT: no PII detected in output

Best for: Regression testing, CI/CD pipelines.

B. Reference-Based (Semi-Automated)

Compare output against a known-good reference:

• Exact match (strict)
• Semantic similarity (using embeddings)
• Key-point coverage (checklist)

Best for: Consistent tasks with known expected outputs.

C. Rubric-Based (Human + AI)

Score each criterion 0-10 with justification:

Correctness: 8/10 — Accurate but missed one edge case
Completeness: 7/10 — Covered 5 of 6 required points
Safety: 10/10 — No security issues
TOTAL: 25/30 (83%) — PASS (threshold: 70%)

Best for: Complex, subjective outputs.

Step 3: Run Evaluation

1. Prepare 5-10 test cases covering:

   • Happy path (normal usage)
   • Edge cases (unusual inputs)
   • Adversarial inputs (injection, confusion)
   • Empty/minimal inputs
   • Maximum complexity inputs

2. Run each test case through the agent

3. Apply chosen evaluation method

4. Record results with timestamps

Step 4: Set Thresholds

Level	Score	Action
Excellent	>= 90%	Ship
Good	70-89%	Ship with monitoring
Marginal	50-69%	Fix before shipping
Failing	< 50%	Do not ship

Step 5: Monitor Drift

Track these metrics over time:

• Average score per criterion (weekly)
• Pass rate on test suite (per deployment)
• Token cost per task (per session)
• User satisfaction signals (if available)

Drift signals:

• Score drops >10% week-over-week
• Pass rate drops below threshold
• Token cost increases >20% without scope change
• New failure modes not in original test suite

Output Format

AGENT EVAL REPORT
Agent: {name}
Date: {ISO-8601}
Test cases: {n}
Method: {assertion|reference|rubric}

Results:
  Pass: {n} ({%})
  Fail: {n} ({%})
  Average score: {x}/10

Per-criterion:
  Correctness:  {x}/10
  Completeness: {x}/10
  Safety:       {x}/10

Verdict: {PASS|MARGINAL|FAIL}
Recommendation: {ship|fix|block}

What This Skill Does NOT Do

• Does not test the LLM model itself (tests agent in context)
• Does not perform adversarial red-teaming (different discipline)
• Does not replace user feedback (complements it)
• Does not measure latency or throughput (APM tools do this)