Semgrep-Rule-Creator: Using Agent to Write Testable Semgrep Security Rules

`semgrep-rule-creator` is an Agent Skill launched by Trail of Bits, used to create custom Semgrep rules that can detect security vulnerabilities, bug patterns and code patterns. Instead of running existing rule sets, it forces the Agent to produce rules following the workflow of test-first, AST analysis, priority given to taint mode, and optimization only after all tests pass. This article organizes the installation method, seven-step workflow, eval taint example and usage boundaries based on the official SKILL.md, plugin README and skill market description.