Codex Agent Creator

When to use

• User asks to create, update, or troubleshoot a custom subagent file in .codex/agents/ or ~/.codex/agents/.
• User needs project or global custom-agent installation with explicit developer instructions.
• User needs constrained global agent runtime settings validation (agents.max_threads, agents.max_depth, agents.job_max_runtime_seconds).
• User asks for upgrades from older role-declaration flows to modern standalone custom-agent files.

Scope and triggers

• Focus on standalone custom-agent authoring, installation, and validation for Codex.
• Do not use this skill for orchestrating active subagent threads or deciding whether the capability should be a skill, prompt, or automation.