diff --git a/documentation/docs/guides/cli-providers.md b/documentation/docs/guides/cli-providers.md
index cf2f9c57..169ac116 100644
--- a/documentation/docs/guides/cli-providers.md
+++ b/documentation/docs/guides/cli-providers.md
@@ -67,7 +67,7 @@ The Codex provider integrates with OpenAI's [Codex CLI tool](https://developers.
 
 **Features:**
 - Uses OpenAI's GPT-5 series models (gpt-5.2-codex, gpt-5.2, gpt-5.1-codex-max, gpt-5.1-codex-mini)
-- Configurable reasoning effort levels (low, medium, high)
+- Configurable reasoning effort levels (`low`, `medium`, `high`, `xhigh`; `none` is only supported on non-codex models like `gpt-5.2`)
 - Optional skills support for enhanced capabilities
 - JSON output parsing for structured responses
 - Automatic filtering of goose extensions from system prompts
@@ -310,7 +310,7 @@ The following models are recognized and passed to the Claude CLI via the `--mode
 | `GOOSE_PROVIDER` | Set to `codex` to use this provider | None |
 | `GOOSE_MODEL` | Model to use (only known models are passed to CLI) | `gpt-5.2-codex` |
 | `CODEX_COMMAND` | Path to the Codex CLI command | `codex` |
-| `CODEX_REASONING_EFFORT` | Reasoning effort level: `low`, `medium`, or `high` | `high` |
+| `CODEX_REASONING_EFFORT` | Reasoning effort level: `low`, `medium`, `high`, or `xhigh` (`none` is only supported on non-codex models like `gpt-5.2`) | `high` |
 | `CODEX_ENABLE_SKILLS` | Enable Codex skills: `true` or `false` | `true` |
 | `CODEX_SKIP_GIT_CHECK` | Skip git repository requirement: `true` or `false` | `false` |