[BUG] Customize → Skills file-tree only renders the first 10 files in a folder; additional reference files are hidden (desktop app + claude.ai)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The Customize → Skills file-tree panel only displays the first 10 files (alphabetically)
inside a skill's references/ folder. Any reference files beyond the 10th are not shown
in the tree at all , the list simply ends at the 10th file and the next sibling skill
begins immediately, with no scrollbar and no "more files" / truncation indicator.

In my case the skill has 13 reference files. The panel shows the first 10; the 3
alphabetically-last files (release-engineering.md, stability-and-gameconfig.md,
version-snapshot.md) never appear.

This is a display/rendering problem, not missing data. The files physically exist in the
active skill directory with full content, the skill loads and uses them at runtime, and the
latest upload clearly synced (a newly added file and the updated description both show up).
The behavior is identical on the Claude desktop app and on claude.ai web, and deleting the
skill and re-adding the full package does not change it , which makes it look to the user
like the upload silently failed or dropped files.

What Should Happen?

The file-tree panel should list all bundled files in a skill's references/ folder,
regardless of how many there are. Anthropic's own Skills documentation states there is no
limit on the number of bundled files and that a skill can include "dozens of reference
files," so all 13 of mine should be visible.

If there is an intentional render cap for performance, the panel should make the remaining
files reachable and obvious , e.g. an internal scrollbar, a "show N more" expander, or
pagination , instead of silently stopping at the 10th file with no indication that more
exist. A user should never be left thinking files are missing when they are present on disk
and used at runtime.

Error Messages/Logs

No error messages or warnings appear anywhere , that silence is part of the problem. There
is no console error, no toast, no truncation indicator in the panel; the file list just
stops at the 10th file.

Diagnostic evidence that the files are present and complete on disk (so this is a UI render
issue, not data loss):

# All 13 reference files exist in the active skill directory:
$ ls -1 "<app-support>/.../skills-plugin/<ids>/skills/<skill-name>/references/" | cat -n
1  ai-behavior-mod-patterns.md
2  alt-scripting-stacks.md
3  asset-pipeline.md
4  audio-modding.md
5  cpp-scripthookv.md
6  csharp-shvdn.md
7  map-and-codewalker.md
8  modpack-assembly.md
9  natives-and-hashes.md
10  reference-projects-2026.md
11  release-engineering.md        <- present on disk, NOT shown in panel
12  stability-and-gameconfig.md   <- present on disk, NOT shown in panel
13  version-snapshot.md           <- present on disk, NOT shown in panel

The three files that the panel omits are exactly files #11–13 in alphabetical order, each
with full, non-empty content, and the skill reads them correctly at runtime.

Steps to Reproduce

This reproduces with any personal skill whose references/ folder has more than 10 files.

Minimal repro — create a throwaway skill with 11 reference files:

1. Make the skill folder and a references subfolder:

mkdir -p /tmp/repro-skill/references

1. Create a minimal SKILL.md:

cat > /tmp/repro-skill/SKILL.md <<'EOF'
---
name: repro-skill
description: Minimal skill to reproduce the references file-tree display cap. Triggers on repro-skill.
---
# Repro Skill
This skill exists only to demonstrate that the Customize → Skills panel
stops listing reference files after the 10th.
EOF

1. Create 11 reference files named so they sort predictably (01..11):

for i in $(seq -w 1 11); do
echo "# Reference file $i" > "/tmp/repro-skill/references/ref-$i.md"
done

1. Zip it into a .skill package:

cd /tmp && zip -r repro-skill.skill repro-skill

1. In the Claude app (or claude.ai), open Customize → Skills → "+" → add repro-skill.skill.

1. Select the skill, expand the references/ folder in the file tree.

Result: only ref-01.md … ref-10.md are listed. ref-11.md is not shown, even though
it is in the package and on disk. Add more files (e.g. 13) and the count shown stays at 10 —
every file past the 10th (alphabetically) is hidden.

Confirmed identical on both the macOS desktop app and claude.ai web. Deleting and re-adding
the package does not change the result.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Unknown , not a confirmed regression. I have no evidence the panel ever showed more than 10 reference files, so I can't point to a last-working version. Treating it as a long-standing display limitation rather than a recent break.

Claude Code Version

2.1.153 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Severity / impact: Low-risk functionally (the skill still works), but high-confusion.
Because the omission is silent and survives re-uploads, it reads as data loss and pushes
users into repeated unnecessary re-uploads and support churn.

Key signal : the cutoff is exactly the first 10, alphabetically: the files shown are
always positions 1–10 in alphabetical order, everything from the 11th onward is hidden.
This points to a hard render/list cap of 10 children per folder rather than a content,
size, or sync problem.

Cross-client: reproduces identically on the macOS desktop app and on claude.ai web, so
it appears to be in the shared Skills panel renderer, not a local cache or OS-specific issue.

Docs say there should be no limit: Anthropic's Skills documentation states bundled files
load on demand and a skill "can include dozens of reference files," so the 10-file ceiling
contradicts the documented design.

Possibly the same family as: #52873 (Customize UI storage-path mismatch), #31597 (skills
not shown in Customize panel), #50669 (UI loads only some skills / doesn't scan directory),
#40231 (skill update path silently truncates files). This may be one more manifestation of
the Customize-UI display/sync layer being out of step with what's actually on disk.

Repro package: a minimal, content-free .skill (11 dummy reference files) that triggers
the bug is available on request , happy to attach it if helpful.

Screenshots attached below: the Customize → Skills panel showing the references/ tree
ending at the 10th file, on both the desktop app and claude.ai web.

<img width="521" height="743" alt="Image" src="https://github.com/user-attachments/assets/30f0734b-f46e-4913-944a-e93a62fe1e6a" />