dsh-write-create-only

write is a full-file overwrite operation. The moment a model mistakenly uses write on an existing file, the original content is wiped out entirely. DSH default fs-observation-policy only requires the file to have been read beforehand and does not forbid overwrites, making post-hoc correction costly and unreliable. dsh-write-create-only turns write into a create-only tool, enforcing the constraint before execution rather than hoping the model behaves.

The plugin registers a global listener in the tools/pre-execute waterfall that activates exclusively for write calls: it performs an fs.stat on the target path first. If the file already exists, the call is denied with a clear message suggesting edit for targeted modifications; if the path is new, execution proceeds as normal. Other tools such as edit and read remain completely unaffected. Uncertain cases like invalid paths or stat errors are always allowed through, ensuring no legitimate call is ever blocked. The rule applies uniformly across all agents and sessions.

Ideal for any DSH workflow involving multi-turn file operations, especially teams that frequently ask models to modify code or documentation. As a pure host-side plugin it touches no DSH internals, mounts automatically on install, and can be removed simply by restarting DSH web. Zero configuration, zero intrusion.