CDX-PL-009: Default Prompt Too Long - Codex CLI

Summary

• Rule ID: CDX-PL-009
• Severity: MEDIUM
• Category: Codex CLI
• Normative Level: MUST
• Auto-Fix: No
• Verified On: 2026-06-04

Applicability

• Tool: codex
• Version Range: >=0.117.0
• Spec Revision: unspecified

Evidence Sources

• https://github.com/openai/codex/blob/rust-v0.137.0/codex-rs/core-plugins/src/manifest.rs

Test Coverage Metadata

• Unit tests: true
• Fixture tests: true
• E2E tests: false

Examples

The following examples demonstrate what triggers this rule and how to fix it.

Invalid

{"name": "my-plugin", "interface": {"defaultPrompt": ["<500+ character prompt string>"]}}

Valid

{"name": "my-plugin", "interface": {"defaultPrompt": ["Fix the login bug"]}}