Long-document question answering usually forces a choice between loading the whole document into the context window and bolting on a separate retriever. Agentic AI suggests a broader option, giving the agent the document path and letting it decide how and what to read. Agent Skills, a standard for packaging expertise into folders an agent loads on demand, supply a ready mechanism: progressive disclosure, which exposes only what a query needs, from a short description down to the specific passages. Practitioners rapidly adopted this pattern for book-length understanding tasks, but the evidence to support such choices has been anecdotal. We run the first controlled study of the pattern, comparing raw-document navigation and several designs of Agent Skills packs against a classical hybrid retriever across three agent harnesses and three model families on ∞Bench. On a single book, the gain depends on the harness, running large when the agent navigates the raw document poorly but near zero when a strong agent harness already divides and retrieves on its own. When scaling up to tasks that span many books, raw-document navigation collapses while one-level progressive disclosure degrades more slowly and pulls ahead. A second, deeper routing level never helps and sometimes breaks accuracy outright, so one level is enough. Progressive disclosure buys context, not intelligence: it is redundant while a strong agent can locate the right passages itself, and decisive once the corpus grows too large to navigate by reading.

Testing is essential to modern software engineering for building reliable software.Given the high costs of manually creating test cases,automated test case generation, particularly methods utilizing large language models,has become increasingly popular.These neural approaches generate semantically meaningful tests that are more maintainable compared with traditional automated testing methods such as fuzzing.However, the diversity and volume of unit tests in current datasets are limited, especially for newer but important languages.In this paper, we present a novel data augmentation technique, FuzzAug,that brings the benefits of fuzzing to large language models by incorporating valid testing semantics and providing diverse coverage-guided inputs.Doubling the size of training datasets,FuzzAug improves performance over the baselines significantly.This technique demonstrates the potential of introducing prior knowledge from dynamic software analysisto improve neural test generation,offering significant enhancements in this task.Our code is open-sourced at https://github.com/SecurityLab-UCD/FuzzAug.