My MCP Tool's Empty-Payload Guard Checks Whether You Passed a Field. It Never Checked Whether the Field Would Actually Change Anything.

Back in early August I fixed a bug in update_article, one of the tools in this repo's DEV.to MCP server. The bug was straightforward: the tool built its PUT payload from three optional parameters, and if a caller passed none of them, it still fired a GET and a PUT with an empty {"article": {}} body against a live published post, then logged a no-op entry to the audit trail as if something had happened. The fix was a guard: raise before either network call if the built payload dict ends up empty.

article = {}

if title is not None:

article["title"] = title

if body_markdown is not None: