Overview
SenseNova-MARS is a multimodal agentic framework enabling Vision-Language Models (VLMs) to perform sophisticated visual reasoning tasks through interleaved tool manipulation and continuous reasoning.
Core Innovation: While VLMs excel at text-oriented reasoning and isolated tool calls, they struggle with coordinated tool sequences on knowledge-intensive visual tasks. SenseNova-MARS enables human-like proficiency in dynamically invoking multiple tools (search, image cropping, text search) to solve complex visual understanding problems.
Architecture
Tool Integration
Three complementary tools enable sophisticated visual problem-solving:
Image Search Tool
- Retrieves semantically related images from knowledge bases
- Supports fine-grained visual understanding through reference images
- Enables comparative analysis across multiple images
Text Search Tool
- Queries knowledge bases for text-based information
- Supports factual grounding of visual analysis
- Bridges visual content with textual knowledge
Image Crop Tool
- Extracts regions of interest from high-resolution images
- Enables focus on fine-grained visual details
- Supports iterative refinement of understanding
Agentic Reasoning Loop
The agent operates through repeated cycles of:
- Perceive - Analyze current visual content and available information
- Reason - Determine which tools would advance understanding
- Act - Invoke appropriate tools (search, crop, etc.)
- Integrate - Synthesize results into improved understanding
RL Training: Batch-Normalized Group Sequence Policy Optimization
To enable reliable tool invocation and reasoning, SenseNova-MARS introduces BN-GSPO algorithm:
Key Components:
- Group Sequence Policy Optimization - Trains on sequences of decisions, not isolated actions
- Batch Normalization - Stabilizes training dynamics in high-variance visual environments
- Reinforcement Signal - Rewards both intermediate tool selections and final correctness
Training Stability Features:
- Handles variable-length action sequences
- Robust to initialization variance in visual encoders
- Supports training with incomplete or noisy rewards
Benchmark Performance
HR-MMSearch (proprietary high-resolution benchmark):
- SenseNova-MARS-32B: 54.4%
- Outperforms Gemini-3-Pro and GPT-5.2
- First benchmark for search-oriented visual understanding
MMSearch Benchmark:
- SenseNova-MARS-32B: 74.3%
- State-of-the-art among open-source models
- Validates framework's effectiveness on knowledge-intensive tasks
Implementation Pattern
Tool Invocation in Agent Loop:
def solve_visual_task(image: PIL.Image, question: str) -> str:
"""Solve visual understanding task through tool orchestration."""
# Initial analysis
context = vlm_analyze(image, question)
# Agentic loop: iteratively invoke tools
reasoning_steps = []
for _ in range(max_steps):
# Determine next action
action = vlm_decide_next_action(context, reasoning_steps)
if action == "image_search":
ref_images = search_visual_db(context.search_query)
context.add_reference_images(ref_images)
elif action == "crop_region":
roi = vlm_identify_roi(image)
cropped = image.crop(roi)
detail = vlm_analyze_detail(cropped)
context.add_detail(detail)
elif action == "text_search":
facts = search_knowledge_base(context.search_query)
context.add_knowledge(facts)
elif action == "answer":
return vlm_synthesize_answer(context, image)
reasoning_steps.append(action)
return vlm_synthesize_answer(context, image)
Advantages Over Single-Tool Approaches
vs. Image-Only Analysis:
- Text search grounds visual understanding in factual knowledge
- Comparative image search provides context for classification
- Handles knowledge-intensive visual tasks (e.g., identifying rare objects)
vs. Text-Only Approaches:
- Preserves fine-grained visual details through image cropping
- Captures spatial relationships between entities
- Enables visual verification of text-based claims
vs. Isolated Tool Invocation:
- Dynamically determines tool sequences based on task progress
- Learns coordination patterns through RL training
- Handles emergent task structures not foreseen during design
When to Use
Use SenseNova-MARS when:
- Solving knowledge-intensive visual tasks (rare object identification, specialized domains)
- Requiring fine-grained visual understanding on high-resolution images
- Needing to ground visual analysis in textual knowledge bases
- Building agents that perform comparative visual analysis
- Requiring robust tool coordination across multiple modalities
When NOT to use:
- Simple image classification or captioning (direct VLM sufficient)
- Real-time applications with strict latency constraints
- Scenarios where tool invocation overhead outweighs benefit
- Tasks with limited textual grounding information available
Related Work
- VLM Tool Use: Gorilla, ToolFormer (static tool selection vs. dynamic agent reasoning)
- Multimodal Reasoning: Unified vision-language architectures (SenseNova-MARS emphasizes tool orchestration)
- RL for VLMs: Limited prior work; SenseNova-MARS demonstrates BN-GSPO's stability
Benchmark Contributions
HR-MMSearch Dataset:
- First search-oriented multimodal benchmark
- High-resolution images with knowledge-intensive questions
- Enables evaluation of tool coordination capabilities
- Publicly available for reproducibility
Code Availability
All code, models, and datasets will be released for community research.
References
- SenseNova-MARS achieves 74.3% on MMSearch, 54.4% on HR-MMSearch
- Outperforms proprietary models Gemini-3-Pro and GPT-5.2
- BN-GSPO algorithm ensures training stability in visual domains
- Demonstrates practical multimodal agent deployment