The bare /compact command compresses your conversation but has to read everything to decide what matters — tool output, file contents, web fetches, search results. That takes minutes and often loses important context.

The fix: tell it what to keep

Create ~/.claude/commands/compact-guide.md with one line:

/compact Focus on: current task, file paths modified, decisions made, user preferences stated. Drop: tool output, search results, web content, file contents already acted on.

Now /compact-guide expands to the full instruction automatically.

Why not compact.md? Claude Code has a built-in /compact command that triggers actual context compression. A custom compact.md overrides it—your instructions expand but compression never happens. Use a different name so both work.

Why it’s faster

A typical session context breakdown:

Tool output (bash, file reads)
~50–60%
Web fetches, search results
~15–20%
Actual conversation + decisions
~15–20%
File contents already acted on
~10%

Without instructions, /compact reads all of it before writing the summary. With instructions, it skips 70–80% of the tokens entirely — only extracting the small slice that actually matters going forward.

The result: seconds instead of minutes, and a leaner summary that leaves more headroom in the next context window.

Customize it for your workflow

Adjust the keep/drop lists to match what you actually need to preserve:

/compact Focus on: current task, file paths modified, decisions made, user preferences stated, open questions. Drop: tool output, search results, web content, file contents already acted on, error messages that were resolved.