Agents Window: non-sensical auto-generated worktree & branch names

Type: Bug

Start a new session from the Agents Window with the worktree option. The name of the automatically generated worktree now is a random name like "agents-prospective-aphid" or "agents-subsequent-loon", where it used to be a sensible name based on the stated task. This makes the Window menu completely useless unless you have the bandwidth to remember which of your current projects is assiciated with which dumb worktree name! (It also makes manual cleanup of stale worktrees much harder - which unfortunately is still often necessary, since it doesn't always work with marking a session 'done')

VS Code version: Code 1.128.0 (fc3def6774c76082adf699d366f31a557ce5573f, 2026-07-07T15:14:24-07:00)
OS version: Darwin arm64 25.5.0
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|Apple M3 Max (16 x 2400)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x106b [Google Inc. (Apple)], DEVICE=0x0000 [ANGLE (Apple, ANGLE Metal Renderer: Apple M3 Max, Version 26.5.1 (Build 25F80))], DRIVER_VENDOR=Apple, DRIVER_VERSION=26.5.1 *ACTIVE*
Machine model name: Mac
Machine model version: 15.9
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: enabled
multiple_raster_threads: enabled_on
opengl: enabled_on
rasterization: enabled
raw_draw: disabled_off_ok
skia_graphite: enabled_on
trees_in_viz: disabled_off
video_decode: enabled
video_encode: enabled
webgl: enabled
webgpu: enabled
webnn: disabled_off|
|Load (avg)|6, 6, 6|
|Memory (System)|48.00GB (0.08GB free)|
|Process Argv|--crash-reporter-id 0a2b75b7-5693-432d-9297-1568853e11a0|
|Screen Reader|no|
|VM|0%|
Extensions (13)

Name|Identifier|Author|Version
---|---|---|---
Bookmarks|alefragnani.bookmarks|alefragnani|14.1.1
Avalonia for VSCode|avaloniateam.vscode-avalonia|AvaloniaTeam|12.2.2
XAML Styler|dabbinavo.xamlstyler|dabbinavo|1.6.1
GitLens — Git supercharged|eamodio.gitlens|eamodio|18.3.0
GitHub Actions|github.vscode-github-actions|github|0.32.1
C# Dev Kit|ms-dotnettools.csdevkit|ms-dotnettools|3.20.199
C#|ms-dotnettools.csharp|ms-dotnettools|2.140.9
.NET Install Tool|ms-dotnettools.vscode-dotnet-runtime|ms-dotnettools|3.1.0
PowerShell|ms-vscode.powershell|ms-vscode|2025.4.0
VS Code Speech|ms-vscode.vscode-speech|ms-vscode|0.16.0
Material Icon Theme|pkief.material-icon-theme|PKief|5.36.1
Image diff viewer|raywiis.png-image-diff|raywiis|0.0.51
TODO Highlight|wayou.vscode-todo-highlight|wayou|1.0.5

A/B Experiments

```
vsliv368:30146709
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
6abeh943:31336334
envsdeactivate2:31538737
cloudbuttont:31379625
3efgi100_wstrepl:31403338
56b7f661:31457055
ec5jj548:31422691
cp_cls_t_966_ss:31526232
8hhj4413:31478653
ge8j1254_inline_auto_hint_haiku:31490510
38bie571_auto:31478677
cp_cls_c_1081:31454833
conptydll_true:31498968
ia-use-proxy-models-svc:31452481
e9c30283:31461165
test_treatment2:31471001
46204921:31447328
control_6dc23131:31544977
idci7584:31464702
e3e4d672:31494082
ei9d7968:31496641
nes-extended-on:31455476
chat:31457767
8hig5102:31480529
89g7j272:31518289
7e187181:31503455
i2gc6536:31499202
52612955:31516516
ghj88844:31499326
ddid_c:31478207
hmra_i5g22:31518061
ja75b849:31547460
ie3bb177:31543534
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
db5d2638:31499441
jb_cp_cls_t_632:31543129
b1ei0813:31506238
748c7209:31512887
32d76977:31512328
ha629193:31508444
cdk-lw-on:31524445
f9bf7985:31543584
a1ije391_t:31540920
api_cot_ctrl:31513533
g4a0e106:31529594
8hfba999:31537718
jbcp_cls_pctr_t:31531130
61138546:31518536
cp_intellij_t_nes:31548657
d7b18187:31526828
nes-curr-leftover-1500:31538366
h561g132:31533256
session_8:31532895
ihg5j128:31534457
f412h606:31546039
9gg7f176:31542112
sandbox-ui-on-2:31543161
nes-nc-lc-2k:31546583

```

Reproduce the issue from the Agents Window by starting a session with the worktree option, then inspect the Agents Window flow and its worktree/branch naming entry point. Done means generated names are again sensible and based on the stated task, remain identifiable in the Window menu, and do not make manual stale-worktree cleanup harder.

Written by the indexing model from the issue text.