The correct command is /clear. In GitHub Copilot CLI, /clear starts a fresh conversational state by removing the current chat history from the active session. This is the appropriate action when the requirement is to discard prior conversation context completely rather than compress or summarize it.

/compact is specifically designed for context management during long-running sessions. It summarizes older conversation history so that useful information can be retained while freeing context-window capacity. Because the question explicitly says ''without summarization,'' /compact does not satisfy the requirement.

/usage displays session consumption and usage information rather than modifying conversation state. /reset-context is not the standard slash command used for clearing Copilot CLI conversation history in this scenario.

The operational distinction is important in agentic workflows. Compaction preserves semantic continuity, while clearing abandons the prior conversational state and gives the agent a clean starting point. Clearing is therefore appropriate when accumulated context has become irrelevant, misleading, or overly large and you deliberately do not want previous reasoning, instructions, or task history carried forward.

Study Guide Reference Topics: Manage Memory, State, and Execution; conversation-state management; context-window control; session reset versus context compaction.