Users often request charts without knowing which database or table holds the relevant data. Such requests may be ambiguous, and users may ask follow-up questions to deepen their analysis or iteratively refine existing charts. A useful assistant must therefore discover relevant data sources among heterogeneous databases, ask clarifying questions when needed, and track evolving user intent while preserving constraints established in earlier turns. Yet recent text-to-visualization agents typically rely on static agent harnesses that are predefined and remain unchanged despite recurring failures across tasks. To address this limitation, we introduce RSIV-Harness, which keeps the language model weights fixed and applies Recursive Self-Improvement to revise the surrounding harness from the agent's own failure traces. To balance flexible self-improvement with stability, we introduce a four-layer framework that evaluates proposed harness revisions through anchor and memory checks, refining those that pass and restoring the best validated harness otherwise. We further introduce ODAC-Vis, a benchmark with 640 tasks for Open-Domain, Ambiguous, and Conversational text-to-visualization that jointly evaluates open-domain data discovery, ambiguity resolution, multi-turn visualization refinement, and executable chart generation. Experiments show that a single round of RSIV-Harness improves all six evaluation metrics relative to the seed harness, with particularly large gains in executability (+28.02 points) and chart structure (+34.01 points), demonstrating the ability to learn from task-solving experience and turn recurring failures across tasks into substantial performance improvements.
Figures & tables
Figure 1. Three challenges in real-world text-to-visualization. The assistant agent needs to discover relevant databases, resolve ambiguous requests before charting, and refine the chart across dialogue turns. Three side-by-side scenarios: discovering databases for a salary chart, clarifying gross versus net sales, and refining a regional sales chart over three dialogue turns.
Dataset
Scale
Domain
Target
Open- domain
Cross- domain
Multi-turn dialogue
Typed ambiguity
Cross- database a
Text2Vis ( Rahman et al., 2025 )
1985 NLQs
103
Python
✗
✗
✓
✓
✗
nvBench 2.0 ( Luo et al., 2025 )
7,878 NLQs
153
Vega-Lite
✗
✗
✗
✓
✗
TACO ( Deng et al., 2026 )
14,500 NLQs
31
SQL
✓
✗
✗
✓
✓
Dial-NVBench ( Song et al., 2024 )
7,244 dialogues
105
VQL
✗
✗
✓
✗
✗
CoSQL ( Yu et al., 2019a )
3,007 dialogues
138
SQL
✗
✓
✓
✓
✗
MultiVis-Bench ( Lu et al., 2026c )
1,202 NLQs
105
Python
✗
✗
✗
✗
✗
Table 1. Comparison of ODAC-Vis with existing benchmarks.
Figure 2. Mean dataset quality scores for ODAC-Vis , Dial-NVBench, and NVBench 2.0 on 100 randomly sampled tasks per benchmark. Panel (a) reports expert blind review; panel (b) reports LLM evaluation with the same three dimensions.
Scale and split
Tasks
640
Tables
1,056
Train / val / test
448 / 96 / 96
Visible databases
206
Domains
139
Test domains
15
Complexity tiers
Single-table
192 30.0%
Single-db join
320 50.0%
Table 2. Scale statistics of ODAC-Vis .
Figure 3. An illustrative task of ODAC-Vis . The first request is unambiguous, so the model retrieves the relevant data and writes a bar chart. A later iteration leaves the measure unspecified; the model asks a clarification question and emits the line chart after the user selects weight.
Figure 4. Architecture of RSIV-Harness . The inner task-solving loop answers one assistant turn under the deployed harness, and the outer self-improvement loop revises that harness from traces accumulated across tasks.
Method
Model
Executability
Route.
Stance
Exec Acc.
Clarify
Chart
Direct Prompt
DeepSeek
81.32
57.59
62.25
31.91
4.32
52.23
GPT
63.04
44.36
61.00
24.51
3.02
47.46
Static Harnesses
DeepSeek
64.98
48.25
51.25
24.51
3.72
41.46
GPT
51.75
30.35
54.00
26.07
2.02
42.01
ReAct
DeepSeek
79.38
57.59
64.25
27.24
3.93
49.57
GPT
65.76
44.75
61.75
21.40
2.27
50.37
Table 3. Overall results on the ODAC-Vis test split across different methods.
Figure 5. Case study on a ODAC-Vis task. The user asks for average driver age by driver, and chooses color by make. Direct Prompt and ReAct change the plotted ages and drivers. H0 concatenates names from the two sources, and MultiVis-Agent changes the bar heights. RSIV-Harness successfully matches user requirements.
Method
Exec.
Route.
Stance
Exec Acc.
Clarify
Chart
RSIV-Harness
93.00
62.26
67.00
31.52
5.15
75.47
- w/o. rule
83.27
59.14
64.50
28.02
2.41
65.94
H0
51.36
48.25
51.25
24.51
3.72
41.46
+ prompt only
87.94
62.26
64.00
29.96
3.76
71.13
+ tool only
84.82
62.26
65.25
27.63
2.84
66.67
+ memory only
85.99
59.92
64.00
26.85
2.56
67.69
Table 4. Ablation of RSIV-Harness on the ODAC-Vis test split. The first variant removes the stability rules. The remaining variants add one evolved component to H0 .
State Key Laboratory of Multimodal Artificial Intelligence Systems, CASIA · School of Artificial Intelligence, University of Chinese Academy of Sciences · New Laboratory of Pattern Recognition, CASIA +1