diff --git a/best-practice/claude-skills.md b/best-practice/claude-skills.md
index 65859b5..6e49ba5 100644
--- a/best-practice/claude-skills.md
+++ b/best-practice/claude-skills.md
@@ -1,6 +1,6 @@
# Skills Best Practice
- 
+ 
[](../implementation/claude-skills-implementation.md)
Claude Code skills — frontmatter fields and official bundled skills.
@@ -14,7 +14,7 @@ Claude Code skills — frontmatter fields and official bundled skills.
---
-## Frontmatter Fields (15)
+## Frontmatter Fields (16)
| Field | Type | Required | Description |
|-------|------|----------|-------------|
@@ -26,6 +26,7 @@ Claude Code skills — frontmatter fields and official bundled skills.
| `disable-model-invocation` | boolean | No | Set `true` to prevent Claude from automatically invoking this skill |
| `user-invocable` | boolean | No | Set `false` to hide from the `/` menu — skill becomes background knowledge only, intended for agent preloading |
| `allowed-tools` | string | No | Tools allowed without permission prompts when this skill is active |
+| `disallowed-tools` | string/list | No | Tools removed from Claude's available pool while the skill is active (e.g. block `AskUserQuestion` for a background loop). Accepts a space/comma-separated string or YAML list — the restriction clears on the next message |
| `model` | string | No | Model to use when this skill runs (e.g., `haiku`, `sonnet`, `opus`) |
| `effort` | string | No | Override the model effort level when invoked (`low`, `medium`, `high`, `xhigh`, `max`) |
| `context` | string | No | Set to `fork` to run the skill in an isolated subagent context |
@@ -36,7 +37,7 @@ Claude Code skills — frontmatter fields and official bundled skills.
---
-##  **(9)**
+##  **(10)**
| # | Skill | Description |
|---|-------|-------------|
@@ -49,6 +50,7 @@ Claude Code skills — frontmatter fields and official bundled skills.
| 7 | `run` | Launch and drive the project's app to see a change working in the real app (not just tests). Requires v2.1.145 |
| 8 | `verify` | Build and run the app to confirm a code change does what it should, without falling back to tests or type checks. Requires v2.1.145 |
| 9 | `run-skill-generator` | Teaches `/run` and `/verify` how to build and launch the project — records a per-project launch recipe at `.claude/skills/run-/`. Requires v2.1.145 |
+| 10 | `simplify` | Review changed code for cleanup opportunities (reuse, simplification, efficiency, abstraction level), four review agents in parallel. From v2.1.154 it does **not** hunt for correctness bugs — use `/code-review` for that |
See also: [Official Skills Repository](https://github.com/anthropics/skills/tree/main/skills) for community-maintained installable skills.