Built-in create-shortcut skill references non-existent set_scheduled_task tool

[bradfeld]

Summary

The built-in create-shortcut skill in Cowork references a set_scheduled_task tool that does not exist in the session's available tool set. This causes Cowork to get stuck when attempting to create scheduled shortcuts.

Steps to Reproduce

1. Start a Cowork session
2. Ask Cowork to create a recurring shortcut/scheduled task (e.g., "create a daily morning briefing shortcut")
3. Cowork loads the create-shortcut skill
4. The skill instructs Claude to "call the set_scheduled_task tool" (line 36 of SKILL.md)
5. Claude cannot find the tool and enters a loop searching for it

Expected Behavior

The set_scheduled_task tool should be available in the session when the create-shortcut skill is loaded, OR the skill should not reference a tool that doesn't exist.

Actual Behavior

Claude's thinking shows it recognizing the problem in real-time:

"The skill says to call set_scheduled_task — this must be a tool available through the skill. Wait, let me re-read the skill instructions. It says 'call the set_scheduled_task tool.' I don't see this explicitly in my tool list."

The session gets stuck and cannot complete the shortcut creation.

Skill File Location

~/Library/Application Support/Claude/local-agent-mode-sessions/<session-id>/.claude/skills/create-shortcut/SKILL.md

Relevant Skill Content (line 36)

Finally, call the "set_scheduled_task" tool.

Environment

• macOS (Darwin 25.1.0)
• Claude Desktop app with Cowork (research preview)
• Max plan
• Date: 2026-02-05

[Rucknar]

Hit this straight out the gate too.

[toni-ppet]

Happened to me but without the create-shortcut skill part. I was experiemnting with Claude Cowork and asked it if it can schedule a task to be run every day at certain time. It used that skill and confidently said the task is scheduled. After the task didn't run I asked why and the answer was "I've investigated the scheduling infrastructure and it appears the native create_scheduled_task platform tool isn't available in this version of Cowork."

[DyrtyJax]

We hit this exact gap in production — the plugin framework expects scheduled/time-based task delivery but the underlying tools don't exist.

We built a full workaround (database storage, cron-based delivery, Slack DM notifications, recurrence handling) and submitted PR #140 with a proactive-reminders skill that documents the pattern. It complements task-management — tasks track what needs doing, reminders deliver a nudge when it's time.

One lesson worth noting: Claude sometimes generates timestamps with the wrong year (2025 instead of 2026), so any scheduled task implementation needs server-side date validation on top of whatever Claude produces.