Text-to-SQL parsing has achieved remarkable progress under the Full Schema Assumption, where the complete database structure is pre-loaded into the model’s context. Yet this assumption overlooks a more fundamental capability question of whether an LLM agent can resolve a query without explicit access to the underlying tables and relations. Moreover, full-schema injection may exceed the effective context window, introduce irrelevant metadata into the reasoning process, and become less reliable as databases evolve. We therefore study the Unknown Schema setting, in which an agent must actively explore the database and commit to only the relevant subset of metadata. To address this, we propose TRUST-SQL (Truthful Reasoning with Unknown Schema via Tools). We formulate the task as a Partially Observable Markov Decision Process in which our autonomous agent follows a structured four-phase protocol to ground reasoning in verified metadata. This protocol provides a structural boundary for our novel Phase-Aware GRPO strategy, which applies token-level masked advantages to isolate exploration rewards from execution outcomes and resolve credit assignment, yielding a 9.9% relative improvement over standard GRPO. Extensive experiments across five benchmarks demonstrate that TRUST-SQL is effective at multiple scales (4B/ 8B/14B). Despite operating entirely without pre-loaded metadata, our agent matches or surpasses prior baselines on most benchmarks that rely on schema prefilling.

Synthetic data generation has emerged as a promising approach to enhance the reasoning capabilities of large language models. However, existing methods remain hindered by high costs—either through expensive API access or additional intermediate training—and are limited in their ability to generalize across different domains. To address these challenges, we propose a multi-agent debate framework based on the Socratic questioning strategy, abbreviated as SoDa. Distinguished from previous methods that prioritize data quantity, we highlight the wisdom of Socratic questioning in augmenting reasoning quality by deepening the thinking process to encourage exploration and broadening it to motivate self-reflection on each question. Combined with our efficient production pipeline, SoDa enables scaling while maintaining affordable costs. We use SoDa to generate diverse datasets for mathematics and code generation tasks with the Qwen2.5-7B-Instruct model, successfully fine-tuning a range of foundation models, from general-purpose ones to OpenAI o1-like ones. For mathematics, the experimental results show that SoDa outperforms the performance of existing datasets at the same scale, achieving improvements ranging from 1.3% to 13.5%. Remarkably, SoDa with 30K examples even surpasses the ScaleQuest dataset with 1000K samples, demonstrating significant efficiency. Our findings highlight the potential of SoDa as a universal, scalable, and cost-effective method for enhancing reasoning capabilities in large models across domains.