Subagents cannot access installed skills that are available to the main agent

Describe the bug

Subagents cannot access installed skills that are available to the main agent

Describe the bug

In GitHub Copilot CLI 1.0.82, a main agent can discover and use skills installed through .copilot/installed-plugins. However, a subagent spawned by that main agent cannot access the same skills.

Instead of invoking the installed skill, the subagent attempts to search for the skill in the current workspace. This fails when the skill is provided by an installed plugin rather than stored in the repository.

This behavior appears to be a regression. The same workflow worked approximately two weeks ago: subagents had access to the same installed skills as the main agent.

Actual behavior

• The main agent can retrieve and use an installed skill successfully.
• A subagent spawned by that agent cannot retrieve the same skill.
• The subagent searches the workspace for the skill instead of resolving it from the installed skills/plugins.

Environment

• GitHub Copilot CLI version: 1.0.82
• Skill source: installed plugins under .copilot/installed-plugins
• Regression window: worked approximately two weeks ago

Why this matters

This breaks workflows where a coordinator agent delegates specialized work to subagents. The parent agent can access the relevant installed skills, but the workers cannot, which makes skill-based orchestration unreliable and forces users to duplicate skill instructions in the repository or pass them manually in prompts.

Requested fix

Please ensure that subagents inherit, or are otherwise given access to, the same installed skills as their parent/main agent. At a minimum, skills from the parent's installed plugin set should be discoverable and invocable by its subagents.

If full inheritance is intentionally not supported, please document the intended scope rules and provide a supported mechanism for declaring skills that a subagent requires.

Affected version

1.0.82

Steps to reproduce the behavior

1. Install a Copilot plugin that provides one or more skills.
2. Verify that the main Copilot CLI agent can discover and invoke one of those installed skills.
3. Ask the main agent to spawn a subagent and explicitly instruct the subagent to use the same skill.
4. Observe that the subagent tries to locate the skill in the repository workspace instead of resolving it from the installed plugin.
5. The subagent therefore cannot invoke the skill that is available to the main agent.

Expected behavior

A subagent should receive access to the same installed skills that are available to its parent/main agent, including skills supplied through .copilot/installed-plugins.

When instructed to use a named skill, the subagent should discover and invoke that installed skill rather than searching the workspace for files or instructions with a matching name.

Additional context

No response

.copilot/installed-plugins にインストールされた plugin を使ってワークフローを再現し、その後、メインエージェントと生成されたサブエージェントの skill discovery を比較します。親エージェントのインストール済み skill セットがサブエージェントにどのように渡されるかを追跡します。サブエージェントが workspace を検索するのではなく、同じインストール済み skill を発見して呼び出せれば完了です。