Context Health Visual

Environment Health

Diagnose the user's Claude Code environment health. Outputs either an inline markdown report or a self-contained interactive HTML dashboard. Covers 10 diagnostic areas — 6 graded scores against official thresholds (§4 splits into §4a at-rest and §4b post-compact; §9 Skill Security Scan uses security baselines rather than docs-cited thresholds) plus 5 observational areas (raw numbers, no tier).

Instructions

Input Parsing

Parse these arguments:

Phase 1 — Data Collection

Determine the context window size. The scan subprocess cannot detect the active session's window from process.env. Derive it from the active model ID:

• Model ID contains [1m] (e.g. claude-opus-4-6[1m]) → 1000000
• Any other model ID → 200000

Pass this as --window-size=<N> so the scan records it and downstream formulas use the correct denominator.

Run the scan:

node ${CLAUDE_PLUGIN_ROOT}/skills/context-health-visual/scripts/env-health-scan.js --window-size=<N>

The script writes a JSON blob to stdout with these sections:

• scan_date, context_window_size, env_and_settings (normalized enable_tool_search per mcp.md's 5-value table, agent_teams_enabled, anthropic_base_url)
• installed_plugins ({plugins, orphan_count, orphans}), disabled_plugins
• installed_skills, installed_commands, local_skills (each entry carries desc_chars, when_to_use_chars, combined_chars, disabled, user_invocable)
• skill_bodies (at-rest 500-line flag + post-compact 5K-token flag)
• hook_inventory (type counts, event collisions, llm_hooks — includes inline hooks from plugin.json's hooks field: schema_issues and schema_issue_counts for hook schema validation)
• skill_security (scanned_count, findings with confidence levels, counts_by_severity, counts_by_category — covers 6 pattern categories: prompt_injection, data_exfil, destructive, hardcoded_credential, obfuscation, safety_override)
• context_metrics (MCP server count + source scopes — includes plugin .mcp.json files AND inline mcpServers from plugin.json)
• plugin_components (bin / monitors / lsp_servers / output_styles / channels per plugin + totals)
• subagent_preloads (agents with skills: frontmatter that preload bodies at start)
• plugin_options (per-plugin option keys only, values omitted — sensitive)
• claude_md (walks cwd → filesystem root + ~/.claude/CLAUDE.md, plus enumerates lazy-loaded nested files below cwd; respects claudeMdExcludes; each entry carries scope, load_mode, compact_resilient)
• rules, memory

Save to /tmp/env-health-<pid>/scan.json.

Optional ground truth refinement:

• If --paste-context is set: use AskUserQuestion to ask for the /context output, parse the reported always-loaded token counts, and override the estimates in the report. Clear the estimate-caveat when doing so.
• If --use-instructions-loaded-hook is set: walk the user through adding a temporary command-type InstructionsLoaded hook to ~/.claude/settings.json that logs to /tmp/env-health-<pid>/instructions-loaded.log. Instruct them to start a new Claude Code session so the hook fires, then parse the log for exact per-file loading. Offer to revert the hook after reading the log.

Phase 2 — Analysis

Read ${CLAUDE_PLUGIN_ROOT}/skills/context-health-visual/references/health-criteria.md for the full threshold specification. Apply it as follows:

Compute the effective description budget:

effective_budget = env_and_settings.desc_budget_override
                ?? max(8000, floor(context_window_size * 0.01))

Graded areas (§3, §4a, §4b, §7, §8, §9): classify into 🟢 healthy / 🟡 attention / 🔴 critical using the rules in health-criteria.md. Every threshold you apply must cite its docs source. (§9 Skill Security Scan is an exception — graded on security baselines without docs-cited thresholds; see health-criteria.md §9.)

Observational areas (§1 Plugin Inventory, §2 Startup Context Budget aggregate, §5 Trigger Collisions, §6 Hook Complexity, §10 Plugin Components): do NOT assign a tier. Emit raw numbers and info-level notes only. Delegate individual component grading in §2 to the owner area per the status-delegation table.

Trigger collisions (§5): delegate to the trigger-collision-inspector subagent. Build the input inventory by concatenating every installed skill and command description, one per line:

[plugin-name] skill-name: description text

Invoke the subagent via the Agent tool with subagent_type set to trigger-collision-inspector. The subagent returns {total_descriptions_analyzed, collisions: [...]}. Surface the pairs verbatim — DUPLICATE / OVERLAP classification is shown as reported, without aggregating into a tier (the prior 1-2 vs 3+ OVERLAP thresholds had no official basis and were removed in favor of raw observation).

Do NOT implement Jaccard or pairwise comparison in the orchestrator or the scan script. The subagent owns the entire comparison (direct adoption of Waza inspector-context.md:113).

Top lever computation: rank possible actions by raw numeric impact (chars freed, tokens saved) — not by severity — so observational areas can still surface a lever. Examples:

• Adding disable-model-invocation: true to the N skills with the largest combined_chars → frees sum(combined_chars) (% of budget). Prefer skills users invoke manually (/commit, /deploy, /release)
• Trimming entries over 1,536 chars → frees combined_chars - 1536 per entry
• Moving body content of a 5K+ token SKILL.md to references/ → removes it from both at-rest and compact budgets

Pick the single lever with the largest projected savings and promote it to the header + recommendations top card.

Phase 3 — Report Generation

Principle: HTML is the default because a dashboard renders the 10 diagnostic areas as KPI cards, bars, and collision heatmaps that markdown can't match. Only choose md when running in a non-browser context (cowork, headless CI), when the user asks for markdown explicitly, or when pasting into a chat thread is more useful than opening a file.

Mermaid generation force-loads Layer 0's semantic-tokens.md (tokens) / diagram-type-selection.md (type mapping) / diagram-density-rules.md (budget) / taste-gate.md (checklist), and is auto-validated by scripts/taste-gate.js.

Markdown mode (--format md):

Emit an inline markdown report with this structure:

# Environment Health — <scan_date>

**Graded:** N 🟢 / N 🟡 / N 🔴 (6 areas) · **Observational:** Plugin Inventory, Context Budget, Trigger Collisions, Hook Complexity, Plugin Components

**Top lever:** <one sentence>

**Estimated startup load:** ~N tokens (X% of <window> window) — *estimate, run `/context` for ground truth*

## §1 Plugin & Skill Inventory ℹ️
<raw tables, orphan/7-day-grace notes, plugin-option keys>

## §2 Startup Context Budget ℹ️
<component breakdown, delegation references>

## §3 Skill Description Obesity <status>
<numbers, truncated entries, disable-model-invocation candidates, subagent preload totals>

## §4 Skill Body Size <status>
<4a at-rest, 4b post-compact — report separately>

## §5 Trigger Collisions ℹ️
<subagent-returned DUPLICATE/OVERLAP pairs, verbatim, no tier>

## §6 Hook Complexity ℹ️
<type breakdown, event collisions, inline-vs-file sources>

## §7 MCP Overview <status>
<server count, ENABLE_TOOL_SEARCH 5-value table, effective mode, proxy fallback>

## §8 CLAUDE.md & Memory Health <status>
<file list with scope/load_mode/compact_resilient, MEMORY.md capacity, nested lazy-loaded totals>

## §9 Skill Security Scan <status>
<findings list with confidence; safe/likely_safe collapsed; hook schema_issues as info notes>

## §10 Plugin Components ℹ️
<bin / monitors / lsp_servers / output_styles / channels per plugin>

## Recommendations
<grouped by severity, top lever promoted>

Cite sources inline where a threshold fires. Keep it under 200 lines.

HTML mode (default, --format html):

Read ${CLAUDE_PLUGIN_ROOT}/skills/context-health-visual/references/section-structure.md for the JSON schema. Then follow ${CLAUDE_PLUGIN_ROOT}/references/report-generation-workflow.md with these parameters:

The sections-data.json must set metadata.report_type = "context-health-visual" so render-sections.js dispatches to the context-health-visual renderers (not the plugin-visual ones).

Privacy guard (both modes): strip any raw file content before rendering. The report emits counts, sizes, line numbers, and file paths — never CLAUDE.md body text, MEMORY.md body text, API keys, or arbitrary file contents. Enforce this as a pre-render pass: walk the sections-data.json tree and remove any field named body, content, raw, text (excluding purposefully-set text fields in info_notes and recommendation action strings, which contain only computed messages).

Cleanup

Remove the temp directory:

rm -rf /tmp/env-health-<pid>

If the user enabled the InstructionsLoaded hook, remind them to revert it now.

Gotchas

• Skill description budget is 1% of context window, not 2%. Earlier drafts used 2% / 16K chars. The official number (skills.md — "Skill descriptions are cut short") is 1% scaling, 8,000-char fallback. Use the effective budget formula: SLASH_COMMAND_TOOL_CHAR_BUDGET ?? max(8000, floor(context_window * 0.01)).
• Skill description loading is a 3-layer model, not a single number. Per skills.md: (A) each entry's combined description + when_to_use is truncated at 1,536 characters — hard per-entry cap. (B) Total across all listing-included entries is capped at effective_budget = SLASH_COMMAND_TOOL_CHAR_BUDGET ?? max(8000, floor(window × 0.01)). When the total exceeds budget, every entry is dynamically shortened (keywords stripped). (C) Even below saturation, a few oversize entries can dominate. Earlier drafts cited "250 chars" — that number does not appear anywhere in the docs. §3 of the report evaluates all three axes separately. disable-model-invocation: true removes a skill from the listing entirely per the frontmatter table, so it contributes zero to the budget.
• 5K/25K skill body limit is POST-COMPACT, not at-rest. The 5,000-tokens-per-skill / 25,000-total limit applies only to re-injection after /compact, and only for skills that were invoked in the session. The at-rest recommendation is separate: keep SKILL.md under 500 lines (skills.md tip). Report them as two distinct sections (§4a and §4b) — do not conflate.
• Skill descriptions are NOT re-injected after compact. Only invoked skills survive compaction. The always-loaded description budget vanishes after compact, which changes what "always-loaded cost" means mid-session. Mention this caveat in the report.
• Auto-compaction can enter a thrashing state and halt. Per how-claude-code-works.md: "If a single file or tool output is so large that context refills immediately after each summary, Claude Code stops auto-compacting after a few attempts and shows an error." The scan cannot detect thrashing directly, but it can surface its ingredients — large SKILL.md bodies, many rules without paths:, and large CLAUDE.md chains all amplify the risk. When all three co-occur, flag it in the report and link users to https://code.claude.com/docs/en/troubleshooting#auto-compaction-stops-with-a-thrashing-error.
• Trigger collision uses a subagent, not inline orchestrator logic. The trigger-collision-inspector subagent owns the entire comparison (Waza-style). Do NOT add Jaccard code in the scanner or do the comparison in the main orchestrator — both would bloat main-session context and duplicate the subagent's job. If accuracy becomes a problem, revise the subagent prompt before adding deterministic pre-filter stages (YAGNI).
• Context budget is always-loaded only. Don't count deferred items in the always-loaded budget unless ENABLE_TOOL_SEARCH is auto (with pressure) or false. Report deferred items separately so users see both views.
• /context is ground truth, not the scan's estimate. The scan uses public formulas but Claude Code's actual context accounting can drift per version. The report must say "Estimated — run /context for ground truth" and optionally accept pasted /context output via --paste-context.
• InstructionsLoaded hook is the file-level ground truth. For users who want exact per-file instruction loading data, recommend temporarily enabling the InstructionsLoaded hook (hooks.md) to log which CLAUDE.md / rules / skills files actually loaded. Offered as --use-instructions-loaded-hook.
• Skill body tokens are estimated (chars/4). Actual tokenization varies. Flag as approximate.
• MEMORY.md path varies by project. The encoded path format can vary. The scan script tries multiple paths — if none match, report "no memory file found" rather than erroring.
• prompt/agent hooks cost tokens per event. Unlike command/http hooks, prompt/agent hook types invoke an LLM call each time they fire. This is a per-event runtime cost, not a startup cost.
• ENABLE_TOOL_SEARCH changes the MCP cost model. The default (deferred) means only tool names in context. auto may load schemas upfront if they fit in 10% of context. false always loads them. The scan reads this env var and adjusts the MCP budget line accordingly.
• claudeMdExcludes and --add-dir CLAUDE.md loading. Respect claudeMdExcludes (exclude matching paths from CLAUDE.md total) and CLAUDE_CODE_ADDITIONAL_DIRECTORIES_CLAUDE_MD=1 (include CLAUDE.md from --add-dir paths). Both affect the always-loaded budget.
• Privacy. The scan reads CLAUDE.md, MEMORY.md, and settings files, but the report must emit counts and sizes only — never file contents, API keys, or memory body text. Enforce as a pre-render guard that strips raw content fields before producing sections-data.json.
• Context window size is not self-detectable from the scan. The node env-health-scan.js subprocess has no way to know the current session's window size (200K vs 1M). Detect it from the active model ID (e.g. claude-opus-4-6[1m] →
  1000000. and pass via --window-size=<N>. Without this, percentage-of-window calculations default to 200K and will be wrong on 1M sessions.
• Shell-level env vars only — child process inheritance. The scan reads SLASH_COMMAND_TOOL_CHAR_BUDGET, ENABLE_TOOL_SEARCH, CLAUDE_CODE_ADDITIONAL_DIRECTORIES_CLAUDE_MD, CLAUDE_CODE_DISABLE_AUTO_MEMORY from process.env. These are only visible to the Node subprocess if the user exported them from their shell init. Env vars set only inside a Claude Code session (not exported before CC launched) are invisible. Surface this caveat next to any env-var-derived field.
• CLAUDE.md walk scope: cwd → filesystem root, plus ~/.claude/CLAUDE.md. Per memory.md, Claude Code loads CLAUDE.md from every ancestor directory above cwd plus ~/.claude/CLAUDE.md. The docs do NOT specify a $HOME boundary. The scan walks up to the filesystem root so that projects under /tmp, /var, or other non-home locations still get a complete ancestor chain. Scope is reported as one of project-root / ancestor / ancestor-local / nested / local-root / user.
• Nested CLAUDE.md files are lazy-loaded and NOT re-injected after /compact. Per memory.md, nested CLAUDE.md files (below cwd) load only when files in their subtree are read. Unlike project-root ./CLAUDE.md / ./.claude/CLAUDE.md, they don't survive compaction — only always-loaded project-root files are re-injected. The scan reports load_mode and compact_resilient per file, and keeps nested_lines / nested_bytes / nested_est_tokens separate from always-loaded totals so the report doesn't exaggerate startup load.
• Observational areas never contribute to the tally. §1 and §2 emit raw numbers and info-level notes only. They are counted separately from the graded tally. A report showing 0 critical means zero critical among graded areas — observational areas may still have info-level observations worth surfacing.
• Skill security scan uses heuristic confidence, not binary safe/unsafe. Every finding is kept in the output — nothing is silently discarded. A confidence field adjusts how prominently findings are shown: safe / likely_safe findings are collapsed by default (temp-path cleanup, loopback-only calls, frontmatter metadata lines, and scanner self-references do not warrant loud alerts). Grade is driven only by uncertain / suspicious findings. When multiple heuristics apply to one finding, the most cautious level (lowest confidence) is used.
• Self-exclusion by frontmatter name:, not by path. The scanner skips the skill whose name: frontmatter field equals context-health-visual. Path-based exclusion would break across install locations (cache vs local). Scope is this skill only — other vision-powers skills (plugin-visual, doc-visual, fact-check, etc.) remain in-scope so any legitimate security findings surface.
• Hook schema validation applies only to tool-gated events. PreToolUse and PostToolUse entries are flagged when they lack a matcher field. Other events (SessionStart, UserPromptSubmit, Stop, etc.) don't use matchers — flagging them would be noise. This scope is hard-coded in env-health-scan.js; update the MATCHER_EVENTS set if future docs add more tool-gated event types.

Reference Files

• references/health-criteria.md — Grading thresholds (cites every docs source) and recommendation templates
• references/section-structure.md — JSON schema for the 10-section HTML report
• agents/trigger-collision-inspector.md — Subagent spec for trigger collision detection (Waza-adapted)
• scripts/env-health-scan.js — Data collection script
• ../../references/report-generation-workflow.md — Shared HTML generation pipeline (render → assemble → validate → log → open)
• ../../references/design-system/semantic-tokens.md — Color and font semantic tokens
• ../../references/design-system/diagram-type-selection.md — 13-type selection guide
• ../../references/design-system/diagram-density-rules.md — Complexity budget per type
• ../../references/design-system/taste-gate.md — Pre-output quality checklist