$skill explicit invocation ignores local explicit-only skills absent from implicit skill list

What version of Codex CLI is running?

codex-cli 0.131.0

What subscription do you have?

ChatGPT auth PRO

Which model were you using?

gpt-5.5

What platform is your computer?

Linux 7.0.3-arch1-2 x86_64 unknown

What terminal emulator and version are you using (if applicable)?

Konsole 26.04.1, tmux 3.6a

Codex doctor report

{
    "overallStatus": "ok",
    "codexVersion": "0.131.0",
    "auth": "ChatGPT auth",
    "model": "gpt-5.5",
    "platform": "linux-x86_64",
    "terminal": "Konsole 26.04.1",
    "multiplexer": "tmux 3.6a",
    "installMethod": "npm",
    "note": "Full doctor output contained local absolute paths and was redacted for public issue."
  }

What issue are you seeing?

After the dumbing down of the underlying GPT-5.5 models recently. Stuff like this is preventing the agent from resolving skills marked with:

policy:
  allow_implicit_invocation: false

Tried with different kinds of reasoning. Was not a problem before.

Should we wait for 5.6 or is it worth addressing?

---

Explicit $skill invocation failed for a local explicit-only skill.

The user invoked:

$act-learn-action

The skill existed at:

.codex/skills/act-learn-action/SKILL.md

Codex did not load it because the skill was absent from the model-visible implicit “Available skills” list. The assistant treated that list as exhaustive and said the named skill was unavailable.

That is incorrect. Explicit-only skills are intentionally not advertised for implicit routing, but $skill should still resolve them.

What steps can reproduce the bug?

1. Install an explicit-only skill under:

.codex/skills/act-learn-action/SKILL.md

1. Start a Codex session where that skill is not listed in the implicit “Available skills” block.

1. Ask Codex:

$act-learn-action update the relevant workflow so this correction is learned

1. Observe that Codex reports the skill unavailable instead of loading the local skill.

What is the expected behavior?

When the user explicitly writes $act-learn-action, Codex should resolve that exact skill name from local configured
skill roots such as .codex/skills.

Explicit-only skills should remain excluded from implicit skill matching, but $skill invocation should be reliable
and should not depend on the implicit “Available skills” list.

Additional information

This appears related to #19695, but this report is specifically about the $skill explicit invocation path.

The key bug is treating the implicit advertised skill list as exhaustive even when the user explicitly invokes a skill
by name.

Chat log:

Me:
$act-learn-action need to update the intake skill or workflows to fix this bullshit

It:
The named $act-learn-action skill is not available in this session, so I’ll use the repo’s create-skill workflow and patch the source skill/workflow files directly. The failure was in approval-artifact selection, so I’m going to find where that workflow is authored and add hard ordering/validation rules there, then rebuild/verify if the repo supports it.