Your Task

Command: $ARGUMENTS

Based on the command:

check - Discover current models, scan all skills, report status
update - Update outdated models to current versions
update --dry-run - Show what would be updated without making changes

Skill Model Updater

You maintain model currency across all skill files, ensuring skills use the latest Claude models.

Step 1: Discover Current Models

Before checking or updating skills, you MUST first discover current model IDs.

Discovery Method

Search for current Anthropic models:

WebSearch: "Anthropic Claude model IDs 2025" OR "Claude API models list current"

Fetch official documentation:

WebFetch: https://docs.anthropic.com/en/docs/about-claude/models

Extract current model IDs for each tier:
- Opus (most capable) - Look for claude-opus-* or claude-*-opus-*
- Sonnet (balanced) - Look for claude-sonnet-* or claude-*-sonnet-*
- Haiku (fast) - Look for claude-haiku-* or claude-*-haiku-*
Identify the latest version of each tier by date suffix (e.g., 20250514 > 20250114)

Expected Output Format

After discovery, report:

CURRENT CLAUDE MODELS (discovered)
==================================
Source: docs.anthropic.com/en/docs/about-claude/models
Date checked: [today's date]

Opus:   claude-opus-4-5-20251101
Sonnet: claude-sonnet-4-5-20250929
Haiku:  claude-haiku-4-5-20251001

Shorthand aliases (always valid, resolve to current):

opus → current opus model
sonnet → current sonnet model
haiku → current haiku model

Workflow

Check Mode

/skill-model-updater check

Discover current models (Step 1 above) - WebSearch/WebFetch Anthropic docs
Glob for all skills/*/SKILL.md files
Extract model: field from YAML frontmatter
Compare against discovered current models
Check CLAUDE.md - Scan ${CLAUDE_PLUGIN_ROOT}/CLAUDE.md for Co-Authored-By: Claude lines and verify model name is current
Report status for each skill and CLAUDE.md

Output format:

SKILL MODEL AUDIT
=================

Current Models (discovered from docs.anthropic.com):
- Opus: claude-opus-4-5-20251101
- Sonnet: claude-sonnet-4-5-20250929
- Haiku: claude-haiku-4-5-20251001

Skill Status:
✓ lyric-writer: claude-opus-4-5-20251101 (current)
✓ researcher: claude-sonnet-4-5-20250929 (current)
⚠ album-art-director: claude-sonnet-4-20250114 (outdated → claude-sonnet-4-5-20250929)
✓ import-audio: claude-haiku-4-5-20251001 (current)

Summary: 19/20 skills current, 1 needs update

Update Mode

/skill-model-updater update

Discover current models (Step 1 above)
Run check to identify outdated skills
For each outdated skill:
- Read the SKILL.md file
- Update the model: field to discovered current version
- Preserve the skill's tier (don't change opus to sonnet)
Update CLAUDE.md - If Co-Authored-By line in ${CLAUDE_PLUGIN_ROOT}/CLAUDE.md references an outdated model name, update it to current
Report changes made

Output format:

SKILL MODEL UPDATE
==================

Models discovered from docs.anthropic.com:
- Opus: claude-opus-4-5-20251101
- Sonnet: claude-sonnet-4-5-20250929
- Haiku: claude-haiku-4-5-20251001

Updated 1 skill:
- album-art-director: claude-sonnet-4-20250114 → claude-sonnet-4-5-20250929

All skills now current.

Dry Run Mode

/skill-model-updater update --dry-run

Same as update but only reports what would change without editing files.

Model Detection Logic

Identifying Outdated Models

A model is outdated if:

It's an older version of a current model family (e.g., claude-sonnet-4-20250114 vs claude-sonnet-4-5-20250929)
It's a deprecated model (e.g., claude-3-opus-20240229)

Tier Detection (Auto)

Detect tier from the skill's existing model: field - no hardcoded tier list needed:

If model contains opus → update to current opus
If model contains sonnet → update to current sonnet
If model contains haiku → update to current haiku
If model is shorthand (opus, sonnet, haiku) → leave as-is (always resolves to current)

This preserves deliberate tier assignments without maintaining a separate mapping.

When New Models Release

This skill discovers models automatically and detects tiers from existing assignments.

When Anthropic releases new models:

Run check - /skill-model-updater check will discover new models automatically
Review changes - Verify discovered models are correct
Run update - /skill-model-updater update to propagate changes

Note: Tier assignments are documented in ${CLAUDE_PLUGIN_ROOT}/reference/model-strategy.md. This skill preserves existing tiers - it only updates version numbers.

Example: Full Update Cycle

User: "New Claude models released, update skills"

1. Run check (discovers models automatically):
   /skill-model-updater check

   Output:
   - Discovered from docs.anthropic.com: Opus 4.5, Sonnet 4, Haiku 3.5
   - 3 skills using outdated sonnet (20250114 → 20250514)
   - 1 skill using deprecated opus (claude-3-opus → claude-opus-4-5)

2. Run dry-run:
   /skill-model-updater update --dry-run

   Output shows proposed changes

3. Run update:
   /skill-model-updater update

   Output confirms 4 skills updated

4. Verify:
   /skill-model-updater check

   Output: All 21 skills current

Error Handling

Missing Model Field

If a SKILL.md has no model: field:

Report as "⚠ [skill]: No model specified"
Do not add one automatically (requires manual decision)

Unknown Model

If a SKILL.md has an unrecognized model:

Report as "? [skill]: Unknown model '[model-id]'"
Do not update (requires manual review)

Invalid YAML

If a SKILL.md has malformed frontmatter:

Report as "✗ [skill]: Invalid YAML frontmatter"
Do not attempt to update

Scope

This skill updates model references in:

All skills/*/SKILL.md files - The model: field in YAML frontmatter
CLAUDE.md - The Co-Authored-By: Claude [Model] <noreply@anthropic.com> line in the versioning section

Both locations must stay in sync with the latest Claude model names.

Remember

Check before update - Always know what will change
Tiers are auto-detected - Skill reads existing model field to determine tier (opus/sonnet/haiku)
Shorthand is safe - opus, sonnet, haiku always resolve to current versions
Tier rationale - See ${CLAUDE_PLUGIN_ROOT}/reference/model-strategy.md for why each skill uses its tier
CLAUDE.md co-author line - Must reflect the current top-tier model name used for commits