[Bug] VS Code extension 2.1.282: IDE sessions start with no core tools - only deferred tools load

Environment

• Windows 10 x64
• VS Code extension anthropic.claude-code 2.1.282 (auto-updated 2026-09-25)
• Standalone CLI (npm) 2.1.267 on the same machine — unaffected
• Extension 2.1.281 — unaffected (downgrade fixes it)

Symptoms

Sessions launched from the VS Code extension start without core tools: Read, Write, Edit, Bash, Glob, Grep, Skill (and likely AskUserQuestion, TodoWrite, Task) are not available. Only deferred/secondary tools load: ToolSearch, WebFetch, WebSearch, CronCreate/CronDelete/CronList, EnterPlanMode/EnterWorktree, NotebookEdit, etc.

The model discovers this mid-session via ToolSearch:

• ToolSearch {"query": "^(Read|Write|Edit|Bash|Glob|Grep|Skill|AskUserQuestion|TodoWrite|Task)$"} → No matching deferred tools found.
• ToolSearch {"query": ".", "max_results": 30} → returns only CronCreate, CronDelete, CronList, EnterPlanMode, EnterWorktree, WebFetch, WebSearch, ... — no core tools anywhere
• A WebFetch fallback attempt on a local path fails with Invalid URL (no Read to fall back on)

The model's own summary: "networking, scheduled tasks and notebook editing are still there; file read/write, shell, file search and skills are all missing."

Evidence (version isolation)

Same machine, same settings, same week:

| Version | Launched from | Core tools | Evidence |
|---|---|---|---|
| 2.1.282 | VS Code (session 1) | ❌ all missing | session jsonl "version":"2.1.282" |
| 2.1.282 | VS Code (session 2, ~5 min later) | ⚠️ partial — Read worked, Skill still missing | session jsonl |
| 2.1.281 | VS Code (previous day) | ✅ normal (Read/Bash used) | session jsonl |
| 2.1.267 | Terminal npm CLI (same day) | ✅ normal | session jsonl |

Repro

1. Let VS Code auto-update the extension to 2.1.282, reload the window
2. Open a folder and start a session
3. Ask Claude to read a local file — it reports having no file tools; ToolSearch for Read finds nothing

Workaround

Downgrade the extension to 2.1.281 ("Install Specific Version...") and disable auto-update for the extension — sessions return to normal.

Notes

• Sessions run against a third-party API gateway; this is excluded as a cause — tool loading happens locally before any API request, and terminal sessions with the identical config and the same gateway work fine on 2.1.267.
• Possibly related to the skill-namespace changes in the 2.1.282 changelog (anthropic-skills / claude-ai skills no longer loading), but the missing core file tools suggest a broader tool-registration regression.
• The second 2.1.282 session partially recovered (Read worked, Skill still missing), hinting at a race with extension activation.