Skill tool incorrectly parses markdown content as Bash command

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 invoking a skill via the Skill tool, the markdown content of the skill file is incorrectly
being run through Bash command permission checking. This causes skill loading to fail when the
content contains characters that look like Bash operators.

The skill fails to load with error:

Bash command permission check failed for pattern "!` non-null assertion without guards

• `": This Bash command contains multiple operations. The following parts require approval:

non-null assertion without guards, -

The ! character inside backticks is being interpreted as a Bash history expansion or negation
operator.

Workaround

Rephrase content to avoid isolated special characters in backticks:

• non-null assertion (!) without guards

Environment

• Claude Code CLI
• macOS (Darwin 24.6.0)

What Should Happen?

The skill content should load successfully. Markdown content should not be parsed as Bash commands.

Error Messages/Logs

Bash command permission check failed for pattern "!` non-null assertion without guards
  - `": This Bash command contains multiple operations. The following parts require approval:
  non-null assertion without guards, -

Steps to Reproduce

Steps to Reproduce

1. Create a skill file (.claude/skills/example/SKILL.md) containing markdown with

backtick-wrapped special characters:

• ! non-null assertion without guards

1. Invoke the skill using the Skill tool

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.0.55

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

_No response_