Interview Bank

Agent Skills in 7 Days: Turn Experience Into Reusable Capability

D7 Capstone and Retrospective: Turning a Team's Conventions Into a Skill Pack and Driving a Subagent Through a Real Task

• What is the difference between running a task in a subagent with skills and running it in the main session?让子代理带着 skill 去执行任务，和在主会话里执行有什么区别？

  Common in ChinaCommon overseasDeep dive#agent-skills#subagent#evaluation

  How to reason about it · think before answering

  1. This tests the value of context isolation. A shallow answer reduces it to opening a new session. Name three effects and the problem each solves.
  2. First, a clean context. A subagent does not inherit the main conversation, so it knows nothing you said or corrected. This is decisive for evaluation: testing a skill in a session you debugged for two hours usually measures your own hints, the most common self-deception here.
  3. Second, precisely bounded capability. A subagent definition can declare its tools, its model, and which skills to preload. For a controlled comparison the two definitions differ only in that line, because any second difference makes the result unattributable.
  4. Third, noise stays out. File reading, trial and error and script runs live in the subagent's own context, and only the conclusion comes back, leaving the main window for the thread that must stay coherent.
  5. Name the costs too. Without the main context, the handoff prompt must be explicit, and a vague task description sends a subagent off course faster than the main session. It also pays for its own system prompt and skill catalog.
  6. An implementation detail shows real experience: skills reach a subagent either by preloading in the definition, which injects the full body at startup, or by letting it discover and activate them during execution. Use preloading for controlled comparisons and discovery for real work.
  7. Expected follow-up: when should you not use one? When the task needs back-and-forth with the user or depends heavily on dozens of earlier turns. There, isolation is the defect rather than the feature.

  分析过程 · 先想清楚再作答

  1. 这题考的是上下文隔离的价值，答得浅会变成「子代理就是开个新会话」。要说清它带来的三件事，以及每一件对应什么问题。
  2. 第一件是**上下文干净**。子代理不继承主会话的对话历史，你说过什么、纠正过什么它一概不知道。这一条在做评估时是决定性的：在调试了两小时的会话里试 skill，模型产出得好往往是因为你自己在会话里把答案说了一遍，这是评估 skill 时最常见的自欺。
  3. 第二件是**能力可以精确限定**。子代理定义里能声明可用工具、模型，也能直接声明预加载哪几个 skill。做对照时两份定义只差这一行，其它完全一致——任何第二个差异都会让结论说不清是谁的功劳。
  4. 第三件是**噪音不进主会话**。翻文件、试错、跑脚本这些过程留在子代理自己的上下文里，只把结论交回来。主会话的窗口因此能留给真正要连贯推进的那条线。
  5. 还要说清代价，只说好处会显得没做过。子代理拿不到主会话的上下文，意味着**交接摘要要写清楚**，任务描述含糊时它比主会话更容易跑偏；而且它多跑一遍系统提示与技能目录，不是免费的。
  6. 补一个实现细节能显出实感：skill 进子代理有两条路，一是在定义里预加载、启动时就注入完整正文，二是让它在执行中自己发现并激活。做对照实验用预加载，因为它把变量固定住了；做真实任务用自动发现，更接近日常。
  7. 可预期的追问是「什么时候不该用子代理」。答案是任务需要跟用户来回确认、或强依赖前面几十轮的上下文时——隔离带来的干净，这时候正好是缺陷。

  Key points

  • A subagent has its own context window and no inherited history, which is what makes a clean comparison possible.
  • Its definition bounds tools, model and preloaded skills, so a controlled pair differs in one line.
  • Process noise stays inside the subagent; only the conclusion returns.
  • The costs are an explicit handoff prompt, more drift on vague tasks, and paying for another system prompt.
  • Preload for controlled experiments, discovery for real work, and skip isolation when the task needs user back-and-forth.

  答题要点

  • 子代理有独立上下文窗口，不继承主会话历史，这是做干净对照的前提。
  • 定义里能限定工具、模型与预加载的 skill，对照时两份定义只差那一行。
  • 过程噪音留在子代理里，只把结论交回主会话。
  • 代价是交接摘要必须写清楚，任务含糊时更容易跑偏，且多付一次系统提示的开销。
  • 预加载适合做对照实验，自动发现更接近真实使用；需要与用户反复确认的任务不适合隔离。