Plugin skills don't support `disable-model-invocation` like user skills do

[johnzfitch]

Summary

User-defined skills support disable-model-invocation: true in YAML frontmatter to hide them from the model's auto-detection. Plugin-defined skills lack this capability, forcing all plugin skills into context regardless of relevance.

Environment

• Claude Code version: 2.1.29
• OS: Arch Linux 6.18.3

The Problem

User Skills (works)

# ~/.claude/skills/my-skill/SKILL.md
---
name: my-skill
description: Does something specific
disable-model-invocation: true
---

Result: Skill hidden from model, only invokable via /my-skill

Plugin Skills (doesn't work)

# ~/.claude/plugins/my-plugin/skills/my-skill/SKILL.md
---
name: my-skill
description: Does something specific
disable-model-invocation: true  # ← Ignored
---

Result: Skill still appears in context, disable-model-invocation has no effect

Context Overhead

From /context command with several plugins installed:

Source	Tokens
Plugin skills	~2,000
Plugin agents	~2,400
Total plugin overhead	~4,400

This overhead is included in every request, with no way to reduce it short of disabling entire plugins.

Impact

• Can't create "manual-only" plugin skills (invoked via /skill-name only)
• Plugin authors can't optimize context usage for their users
• Users must choose between plugin functionality and context efficiency

Expected Behavior

disable-model-invocation: true should work identically for:

• User skills in ~/.claude/skills/
• Plugin skills in ~/.claude/plugins/*/skills/

Proposed Solution

1. Parse disable-model-invocation from plugin skill frontmatter
2. Exclude matching skills from model context
3. Keep skills invokable via /plugin:skill-name syntax

Workaround

Currently none. Users must either:

• Accept the context overhead, or
• Disable the entire plugin

Skill Index Pattern (partial workaround)

Create one auto-detect skill that lists all others:

• 1 skill in context (~26 tokens) vs 20+ skills (~2K tokens)
• Other skills invoked manually via /skill-name

This requires plugin authors to restructure their plugins.

---

Token Impact

Per-Request Overhead

This overhead is included in every request, not just when using plugins:

Requests/Session	Plugin Overhead	With disable-model-invocation*
10	44K tokens	~11K tokens
50	220K tokens	~55K tokens
100	440K tokens	~110K tokens

*Assuming 75% of plugin skills marked as manual-only

Monthly Cost at Scale

Sessions/Month	Current Overhead	Optimized	Savings
100	~$66	~$17	$49
500	~$330	~$83	$247
1000	~$660	~$165	$495

(Based on Sonnet input pricing: $3/1M tokens)

---

Related Issues

• LSP plugins spawn eagerly regardless of file types in project #22335 - LSP plugins spawn eagerly regardless of file types
• Subagents should receive distilled system prompts tailored to their role #22344 - Subagent system prompt bloat
• [BUG] Custom plugin subagents cannot access MCP tools (built-in agents can) #13605 - Custom plugin subagents cannot access MCP tools

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] Skill-scoped hooks defined in SKILL.md frontmatter are not triggered within plugins #17688
2. [BUG] Skill frontmatter model: field documented but not working #21679
3. [BUG] Plugin skills with name in frontmatter lose their plugin prefix #22063

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[johnzfitch]

Not a duplicate. The suggested issues are different:

Issue	About	This issue
#17688	Skill-scoped hooks not triggered in plugins	disable-model-invocation frontmatter
#21679	model: field not working	disable-model-invocation field
#22063	Plugin prefix lost with name in frontmatter	disable-model-invocation behavior

This issue is specifically about disable-model-invocation: true working for user skills but not plugin skills - none of the suggested duplicates cover this.

[turlockmike]

This bug consumes a lot of tokens.