[BUG] Managed skill fails with 404 "model: haiku" - invalid model ID

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Description

When using a managed skill (e.g., /guidelines), Claude Code fails with a 404 API error because it's passing haiku as the model name instead of a valid model ID.

## Error Message

API Error: 404 {"type":"error","error":{"type":"not_found_error","message":"model: haiku"},"request_id":"req_011CWpsBvxrs8RboJEh4fswy"}

## Environment

• Claude Code Version: 2.0.76
• OS: Windows 11
• Node Version: v22.21.1

## Actual Behavior

The skill passes haiku as the model name, which the Anthropic API doesn't recognize, returning a 404 not found error.

## Workaround

Manually read the files that the skill would have accessed instead of using the skill.

## Additional Context

The skill definition shows:
The issue appears to be in how managed skills specify their model - using a shorthand haiku that isn't valid for the API.

What Should Happen?

The skill should use a valid model ID like claude-3-5-haiku-20241022 or claude-3-haiku-20240307.

Error Messages/Logs

Let me first read the guidelines and then explore the relevant code.

● /guidelines
  ⎿  API Error: 404 {"type":"error","error":{"type":"not_found_error","message":"model:
     haiku"},"request_id":"req_011CWpthN2ue2ZjrCenfzdQh"}

Steps to Reproduce

1. Start a new Claude Code session in a project with a managed skill
2. Have Claude attempt to use the skill (e.g., /guidelines)
3. The skill fails with the 404 error above

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.0.76 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_