Description

If a task is moved from one tag to another and its number already exists in the destination tag, an error is thrown and the task is not moved. This relates to the tool mcp__task-master__move_task

The only way to move tasks is to

1. renumber the tasks to free slots in the receiving tag
2. move the tasks to the chosen tag

Steps to Reproduce

Just create a task within a tag another within another tag, both having the same task number, move the first one to the other tag and the conflicting task number will lead to an error. Doing it with any agent.

Expected Behavior

When moving tasks from one tag to another, the moved task should be renumbered to available slots in the receiving tag. As well as bringing task dependencies in sync with the new numbering. Also, if closed tasks were dependencies they should be moved along even if not specified, though cross-tag dependencies would be more elegant and simpler in case of complex dependencies. In absence of cross-tag dependencies, open task that are dependencies or are dependent on the moved tasks but not included in the moved tasks should yield an error.

Actual Behavior

Described above.

Environment

• Task Master version: 0.43.0
• Node.js version: 25.8.0
• Operating system: macOS 15.7.5 Sequoia
• IDE (if applicable): Claude Code

Additional Context