[Observation]: Copilot SDK 1.0.x is less willing to load skills

My team has recently upgraded Copilot SDK from 0.3.x to 1.0.x for running a few fixed scenarios to track the agent behavior with our skills. We give the agent a generic documentation tool that searches in MS Learn and skills with service oriented instructions. We noticed that after upgrading to Copilot SDK 1.0.x, the agent shows a much higher likelihood to use documentation tools instead of loading a skill. This is not an ideal behavior. Local skills are usually knowledge the user creates to override the generic knowledge in the training data or public documentation. They are also usually more efficient in token usage.

未指定任何文件、测试或入口点。首先使用 MS Learn 文档工具和本地技能，在 Copilot SDK 0.3.x 和 1.0.x 中复现这些固定场景，然后确定何时会绕过技能加载。完成的标准是就预期的优先级达成一致，并确定一个用于验证或更改该行为的具体位置。

由索引模型根据 Issue 内容生成。