Problem
Current LLM agent evaluation relies on narrow benchmarks:
- Limited Domains: Most benchmarks test single skills (QA, tool use, reasoning)
- Unrealistic Complexity: Real-world agents face simultaneous constraints and dynamic environments
- Missing Capability Assessment: No systematic measurement of planning, adaptation, and strategic reasoning
- Hallucination Blindness: Benchmarks don't explicitly measure when agents fabricate information
- Human-Agent Gap Unknown: Unclear how far agents lag behind human performance on complex tasks
Agents need evaluation frameworks that measure real-world reasoning capabilities beyond text understanding.
Solution
TowerMind introduces a Tower Defense Game Benchmark for LLM agents:
- Multimodal Observations: Agents receive three observation types:
- Pixel-Based: Raw game visuals (tower positions, enemy locations)
- Textual: Natural-language game state descriptions
- Structured: JSON game state with numeric values
- Strategic Complexity: Tower defense requires simultaneous optimization:
- Planning: Predict enemy paths and plan tower placement
- Resource Management: Budget constraints on tower construction
- Adaptation: Adjust strategies as enemy waves change
- Explicit Hallucination Measurement: Benchmark includes scenarios designed to expose fabricated knowledge
- Out-of-place game elements
- Contradictions between observation modes
- Impossible win conditions
When to Use
- Agent Capability Assessment: Measure planning, adaptation, and strategic reasoning
- Multimodal Evaluation: Test agents on multiple observation formats
- Hallucination Testing: Diagnose tendency to fabricate information
- Comparative Benchmarking: Track agent improvements across versions
- Planning Validation: Verify that agents think ahead vs. reacting locally
- Academic Research: Study how LLMs approach real-time strategy
When NOT to Use
- For production deployment decisions (game performance doesn't predict real-world capability)
- For single-domain specialists (game tests general reasoning, not domain expertise)
- In latency-critical applications (game simulation adds evaluation overhead)
- For systems already operating well on established benchmarks
Core Concepts
The framework operates on the principle that complex games reveal agent reasoning:
- Multifinality Challenge: Multiple ways to solve tower defense force strategic thinking rather than pattern matching
- Dynamic Environment: Enemies change paths → agents must adapt plans, not execute pre-learned scripts
- Quantifiable Performance: Win/loss, score, survival time provide clear metrics
- Hallucination Visibility: Game rules are learnable; invented rules become obvious
Key Implementation Pattern
Evaluating agents on TowerMind:
# Conceptual: agent evaluation on TowerMind
class TowerMindBenchmark:
def evaluate_agent(self, agent, num_episodes=10):
results = {
'win_rate': 0,
'planning_validity': 0,
'adaptation_score': 0,
'hallucination_count': 0
}
for episode in range(num_episodes):
# Step 1: Provide multimodal observation
obs_pixels, obs_text, obs_structured = self.get_observation()
agent.receive_observation(obs_pixels, obs_text, obs_structured)
# Step 2: Get agent plan
plan = agent.generate_plan()
results['planning_validity'] += self.validate_plan(plan)
# Step 3: Execute and track adaptation
for step in range(max_steps):
action = agent.choose_action()
# Check for hallucination: action requires non-existent tower
if self.is_hallucinated_action(action):
results['hallucination_count'] += 1
obs_pixels, obs_text, obs_structured = self.step(action)
agent.update(obs_pixels, obs_text, obs_structured)
# Step 4: Score episode
if self.won(episode):
results['win_rate'] += 1
results['adaptation_score'] += self.measure_adaptation()
return {k: v / num_episodes for k, v in results.items()}
Key evaluation metrics:
- Win Rate: Percentage of games successfully completed
- Planning Validation: Are proposed plans executable?
- Adaptation Score: Do agents adjust strategy when environment changes?
- Hallucination Count: How often does agent reference non-existent game elements?
Expected Outcomes
- Baseline Performance Gap: Current LLMs achieve 20-30% win rate vs. 80%+ for human experts
- Capability Diagnostics: Identify specific weaknesses (inadequate planning, rigid strategy)
- Multimodal Insights: Measure how agents perform with pixel vs. text vs. structured observations
- Hallucination Quantification: Explicit counts of fabricated game state claims
Limitations and Considerations
- Tower defense performance doesn't directly predict capability in other domains
- Simulation overhead makes TowerMind slower than text-based benchmarks
- Some agents may perform poorly due to interaction interface limitations rather than reasoning
- Game difficulty varies; may need level selection for fair agent comparison
Benchmark Structure
Includes:
- Level Progression: Increasing difficulty from basic to expert
- Multimodal Variants: Test agents with different observation types
- Hallucination Scenarios: Explicit tests for fabrication tendencies
- Human Baseline: Expert player scores for reference
- Adaptation Tests: Dynamic enemy waves force strategy revision
Use for comprehensive agent evaluation.
Integration in Agent Development
For an agent development pipeline:
- Train Agent: On standard benchmarks
- Evaluate on TowerMind: Measure planning, adaptation, hallucination
- Diagnose Weaknesses: Identify specific capability gaps
- Iterate: Target improvements based on benchmark feedback
- Track Progress: Monitor improvement across versions
This systematic evaluation catches capabilities standard benchmarks miss.
Related Work Context
TowerMind addresses the evaluation gap by providing a complex, real-time environment that demands planning, adaptation, and strategic reasoning. Unlike narrow task-specific benchmarks, tower defense captures the multifaceted nature of agent reasoning.