{
  "version": 1,
  "note": "Machine-readable best-practices register. SOURCE OF TRUTH for the optimization lens (v5.7 CA-OPT). Human-readable mirror lives in knowledge/*.md. Every entry is provenance-stamped (source.url + source.verified) and carries a confidence; only CONFIRMED claims are consumed user-facing (Verifiseringsplikt). Curated manually + by /config-audit knowledge-refresh (human-approved). Seeded from docs/v5.5-steering-model-plan.md V-rows + the Anthropic 'Steering Claude Code' blog.",
  "entries": [
    {
      "id": "BP-MECH-001",
      "claim": "Lifecycle automation phrased as an instruction in CLAUDE.md (\"every time\", \"before each\", \"always run X after Y\") should be a hook — a behavior the model chooses to follow is not deterministic.",
      "mechanism": "hook",
      "appliesTo": "claude-md",
      "recommendation": "Move the behavior to a PreToolUse/PostToolUse/Stop hook so it runs deterministically, outside the model's discretion.",
      "confidence": "confirmed",
      "severity": "low",
      "category": "mechanism-fit",
      "lensCheck": "claude-md-lifecycle-phrasing",
      "source": { "url": "https://claude.com/blog/steering-claude-code-skills-hooks-rules-subagents-and-more", "title": "Steering Claude Code: skills, hooks, rules, subagents and more", "verified": "2026-06-20" }
    },
    {
      "id": "BP-MECH-002",
      "claim": "A file- or path-specific constraint placed in root CLAUDE.md or an unscoped rule should be a path-scoped rule (paths: frontmatter), so it loads only when a matching file is touched.",
      "mechanism": "rule",
      "appliesTo": "claude-md",
      "recommendation": "Move it to .claude/rules/ with a paths: frontmatter; unscoped instructions cost tokens every turn whether relevant or not.",
      "confidence": "confirmed",
      "severity": "low",
      "category": "mechanism-fit",
      "lensCheck": "unscoped-path-specific-instruction",
      "source": { "url": "https://claude.com/blog/steering-claude-code-skills-hooks-rules-subagents-and-more", "title": "Steering Claude Code: skills, hooks, rules, subagents and more", "verified": "2026-06-20" }
    },
    {
      "id": "BP-MECH-003",
      "claim": "A multi-step procedure (deploy/release checklist) in CLAUDE.md should be a skill — CLAUDE.md is for facts Claude should hold all the time; procedures belong in skills.",
      "mechanism": "skill",
      "appliesTo": "claude-md",
      "recommendation": "Extract the procedure into .claude/skills/; its body then loads only on invoke instead of every turn.",
      "confidence": "confirmed",
      "severity": "low",
      "category": "mechanism-fit",
      "lensCheck": "procedure-in-claude-md",
      "source": { "url": "https://claude.com/blog/steering-claude-code-skills-hooks-rules-subagents-and-more", "title": "Steering Claude Code: skills, hooks, rules, subagents and more", "verified": "2026-06-20" }
    },
    {
      "id": "BP-MECH-004",
      "claim": "An absolute prohibition phrased as a \"never do X\" instruction is the wrong tool; for something that absolutely must not happen, use permissions or a PreToolUse hook.",
      "mechanism": "permission",
      "appliesTo": "claude-md",
      "recommendation": "Enforce hard prohibitions via permission deny rules or a PreToolUse hook (exit code 2 denies the call), not prose instructions.",
      "confidence": "confirmed",
      "severity": "low",
      "category": "mechanism-fit",
      "lensCheck": "never-instruction",
      "source": { "url": "https://claude.com/blog/steering-claude-code-skills-hooks-rules-subagents-and-more", "title": "Steering Claude Code: skills, hooks, rules, subagents and more", "verified": "2026-06-20" }
    },
    {
      "id": "BP-MECH-005",
      "claim": "A custom output style without keep-coding-instructions: true removes Claude Code's built-in software-engineering instructions when active.",
      "mechanism": "output-style",
      "appliesTo": "output-style",
      "recommendation": "Set keep-coding-instructions: true, or prefer a built-in style (Explanatory / Learning / Proactive) before writing a custom one.",
      "confidence": "confirmed",
      "severity": "medium",
      "category": "mechanism-fit",
      "lensCheck": "CA-OST-001",
      "source": { "url": "https://code.claude.com/docs/en/output-styles", "title": "Output styles", "verified": "2026-06-20" }
    },
    {
      "id": "BP-LOAD-001",
      "claim": "Project-root CLAUDE.md and unscoped rules are re-injected from disk after compaction (they survive a /compact).",
      "appliesTo": "claude-md",
      "confidence": "confirmed",
      "category": "loading-model",
      "lensCheck": null,
      "source": { "url": "https://code.claude.com/docs/en/context-window", "title": "Context window — what survives compaction", "verified": "2026-06-20" }
    },
    {
      "id": "BP-LOAD-002",
      "claim": "Path-scoped rules are lost after compaction until a matching file is read again, and they trigger on Read of a matching file (not on every tool use).",
      "appliesTo": "rule",
      "confidence": "confirmed",
      "category": "loading-model",
      "lensCheck": null,
      "source": { "url": "https://code.claude.com/docs/en/memory", "title": "Memory — path-specific rules", "verified": "2026-06-20" }
    },
    {
      "id": "BP-LOAD-003",
      "claim": "A nested (non-root) CLAUDE.md is lost after compaction until a file in its directory is read again.",
      "appliesTo": "claude-md",
      "confidence": "confirmed",
      "category": "loading-model",
      "lensCheck": null,
      "source": { "url": "https://code.claude.com/docs/en/context-window", "title": "Context window — what survives compaction", "verified": "2026-06-20" }
    },
    {
      "id": "BP-LOAD-004",
      "claim": "A skill's name + description load every turn; its body loads only on invoke.",
      "appliesTo": "skill",
      "confidence": "confirmed",
      "category": "loading-model",
      "lensCheck": null,
      "source": { "url": "https://code.claude.com/docs/en/skills", "title": "Skills", "verified": "2026-06-20" }
    },
    {
      "id": "BP-LOAD-005",
      "claim": "Hook scripts run outside the model context, but any additionalContext they inject is saved to the transcript and is therefore subject to compaction.",
      "appliesTo": "hook",
      "confidence": "confirmed",
      "category": "loading-model",
      "lensCheck": null,
      "source": { "url": "https://code.claude.com/docs/en/hooks", "title": "Hooks", "verified": "2026-06-20" }
    },
    {
      "id": "BP-LOAD-006",
      "claim": "A subagent runs in an isolated, fresh context window; only its final summary returns to the main session (parent instructions are not auto-injected).",
      "appliesTo": "agent",
      "confidence": "confirmed",
      "category": "loading-model",
      "lensCheck": null,
      "source": { "url": "https://code.claude.com/docs/en/sub-agents", "title": "Subagents", "verified": "2026-06-20" }
    },
    {
      "id": "BP-SIZE-001",
      "claim": "Keep CLAUDE.md under 200 lines; give it an owner and review changes to it like code. Every line costs tokens whether relevant or not.",
      "appliesTo": "claude-md",
      "recommendation": "Trim CLAUDE.md to facts; move procedures to skills and path-specific rules to .claude/rules/.",
      "confidence": "confirmed",
      "severity": "medium",
      "category": "size-budget",
      "lensCheck": "CA-CML-001",
      "source": { "url": "https://claude.com/blog/steering-claude-code-skills-hooks-rules-subagents-and-more", "title": "Steering Claude Code: skills, hooks, rules, subagents and more", "verified": "2026-06-20" }
    },
    {
      "id": "BP-SIZE-002",
      "claim": "The skill-listing description cap is 1,536 characters (maxSkillDescriptionChars, configurable, v2.1.105+); the name + description load every turn.",
      "appliesTo": "skill",
      "confidence": "confirmed",
      "severity": "low",
      "category": "size-budget",
      "lensCheck": "CA-SKL-002",
      "source": { "url": "https://code.claude.com/docs/en/skills", "title": "Skills", "verified": "2026-06-20" }
    }
  ]
}