Agent Skills: Strategic Compact Skill

Strategic Compact Skill

Suggests manual /compact at strategic points in your workflow rather than relying on arbitrary auto-compaction.

When to Activate

• Running long sessions that approach context limits (200K+ tokens)
• Working on multi-phase tasks (research → plan → implement → test)
• Switching between unrelated tasks within the same session
• After completing a major milestone and starting new work
• When responses slow down or become less coherent (context pressure)

Why Strategic Compaction?

Auto-compaction triggers at arbitrary points:

• Often mid-task, losing important context
• No awareness of logical task boundaries
• Can interrupt complex multi-step operations

Strategic compaction at logical boundaries:

• After exploration, before execution — Compact research context, keep implementation plan
• After completing a milestone — Fresh start for next phase
• Before major context shifts — Clear exploration context before different task

How It Works

The suggest-compact.js script runs on PreToolUse (Edit/Write) and:

1. Tracks tool calls — Counts tool invocations in session
2. Threshold detection — Suggests at configurable threshold (default: 50 calls)
3. Periodic reminders — Reminds every 25 calls after threshold

Hook Setup

Add to your ~/.claude/settings.json:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Edit",
        "hooks": [{ "type": "command", "command": "node ~/.claude/skills/strategic-compact/suggest-compact.js" }]
      },
      {
        "matcher": "Write",
        "hooks": [{ "type": "command", "command": "node ~/.claude/skills/strategic-compact/suggest-compact.js" }]
      }
    ]
  }
}

Configuration

Environment variables:

• COMPACT_THRESHOLD — Tool calls before first suggestion (default: 50)

Compaction Decision Guide

Use this table to decide when to compact:

| Phase Transition | Compact? | Why | |-----------------|----------|-----| | Research → Planning | Yes | Research context is bulky; plan is the distilled output | | Planning → Implementation | Yes | Plan is in TodoWrite or a file; free up context for code | | Implementation → Testing | Maybe | Keep if tests reference recent code; compact if switching focus | | Debugging → Next feature | Yes | Debug traces pollute context for unrelated work | | Mid-implementation | No | Losing variable names, file paths, and partial state is costly | | After a failed approach | Yes | Clear the dead-end reasoning before trying a new approach |

What Survives Compaction

Understanding what persists helps you compact with confidence:

| Persists | Lost | |----------|------| | CLAUDE.md instructions | Intermediate reasoning and analysis | | TodoWrite task list | File contents you previously read | | Memory files (~/.claude/memory/) | Multi-step conversation context | | Git state (commits, branches) | Tool call history and counts | | Files on disk | Nuanced user preferences stated verbally |

Best Practices

1. Compact after planning — Once plan is finalized in TodoWrite, compact to start fresh
2. Compact after debugging — Clear error-resolution context before continuing
3. Don't compact mid-implementation — Preserve context for related changes
4. Read the suggestion — The hook tells you when, you decide if
5. Write before compacting — Save important context to files or memory before compacting
6. Use /compact with a summary — Add a custom message: /compact Focus on implementing auth middleware next

Token Optimization Patterns

Trigger-Table Lazy Loading

Instead of loading full skill content at session start, use a trigger table that maps keywords to skill paths. Skills load only when triggered, reducing baseline context by 50%+:

| Trigger | Skill | Load When | |---------|-------|-----------| | "test", "tdd", "coverage" | tdd-workflow | User mentions testing | | "security", "auth", "xss" | security-review | Security-related work | | "deploy", "ci/cd" | deployment-patterns | Deployment context |

Context Composition Awareness

Monitor what's consuming your context window:

• CLAUDE.md files — Always loaded, keep lean
• Loaded skills — Each skill adds 1-5K tokens
• Conversation history — Grows with each exchange
• Tool results — File reads, search results add bulk

Duplicate Instruction Detection

Common sources of duplicate context:

• Same rules in both ~/.claude/rules/ and project .claude/rules/
• Skills that repeat CLAUDE.md instructions
• Multiple skills covering overlapping domains

Context Optimization Tools

• token-optimizer MCP — Automated 95%+ token reduction via content deduplication
• context-mode — Context virtualization (315KB to 5.4KB demonstrated)

Related

• The Longform Guide — Token optimization section
• Memory persistence hooks — For state that survives compaction
• continuous-learning skill — Extracts patterns before session ends