# B2: per-profile plugin-enablement overlays — shipped + measured

_Task: B2 in [system-prompt-profiles-tasks.md](system-prompt-profiles-tasks.md) ·
2026-07-08 · Depends on C3 findings ([c3-spike-findings.md](c3-spike-findings.md))_

## Pre-check result: `enabledPlugins` DEEP-MERGES

The open item from C3 is resolved empirically (transcript `skill_listing` inspection, two
headless haiku runs): a `--settings <overlay.json>` file's `enabledPlugins` is merged
key-by-key into `~/.claude/settings.json` — only the plugins explicitly set `false`
disappear (baseline 64 skills → 61, exactly the 3 skills of the 2 disabled plugins);
unlisted plugins and all hooks are unaffected. **Diff-only overlays are safe.**

## Shipped

`~/.claude/profiles/` (see its README.md):

- `cc-os-design.json` — disables rails-ui-component, api-wrapper, invoice-ninja,
  creative-team, dev-team
- `client-dev.json` — disables creative-team, invoice-ninja, arch-refactor
- `brainstorm.json` — disables all 9 coding/client plugins (adds ruby-lsp, codex,
  git-context, arch-refactor)

Usage: `claude --settings ~/.claude/profiles/<name>.json`. Never combine with a
`--setting-sources` list that omits `user` (silent plugin/hook drop — see vault note
`claude-code-setting-sources-silent-plugin-drop`).

## Measured savings (headless haiku, empty dir, 2026-07-08)

| Run | Context tokens | Delta vs baseline |
|---|---|---|
| baseline (no overlay) | 29,045 | — |
| cc-os-design (5 plugins off) | 29,013 | −32 |
| brainstorm (9 plugins off) | 28,413 | −632 |

**Honest verdict: token savings are marginal.**

## Follow-on: YAGNI tool deny (2026-07-08, same session)

Transcript sweep of all sessions since 2026-06-01 (tool_use counts across
`~/.claude/projects/**/*.jsonl`): heavy use of Bash (7.7k) / Read (4.2k) / Edit (2.1k) /
Agent (1.3k) / Write (1.2k); **zero-or-one lifetime calls** to Workflow, Artifact,
SendUserFile, ReportFindings — all of which ship full schemas up front (not deferred).

Measured (headless haiku, empty dir): disallowing Workflow alone −5,982 tokens
(its schema ≈ the whole system-prompt text); all four −6,509. A `permissions.deny`
block in a settings file removes the schemas identically to `--disallowedTools`
(22,532 vs 22,536).

**Applied globally** to `~/.claude/settings.json`:
`"permissions": {"deny": ["Workflow", "Artifact", "SendUserFile", "ReportFindings"]}` —
~6.5k saved every session, no flags needed. Revert by deleting the entry (needed if
"ultracode"-style Workflow orchestration is ever wanted). This delivers the
"`--tools` restriction is the real lever" prediction from the assessment; A1/A2's
remaining value is now just the interactive-Fable confirmation. The assessment's "~4.8k user stack"
is dominated by hooks/memsearch injection and per-plugin fixed listings, not by the
skill descriptions the overlays remove — ToolSearch deferral already made plugin
skills cheap. The remaining value of profiles is **focus** (no irrelevant slash
commands/agents offered in a brainstorm session), not context cost. This further
deprioritizes Wave 3 (aliases: trivial, do when friction is felt) and Group D
(dropped), and shifts remaining token-diet attention to the memsearch injection
(~1.5–3.9k/session, needs upstream fix — see b3-memsearch-injection-review.md).
