Developer finds his MCP server's safety gates can be bypassed by omission

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A developer building an MCP server for his DEV.to publishing pipeline discovered that two safety checks he added to prevent accidental overwrites of live articles were not true permission boundaries. The tool 'update_article' was designed to require a 'confirm=True' flag before editing published content, since DEV.to stores no version history, but the developer realized any agent or caller could simply pass 'confirm=True' on the first call without ever going through the preview step. A second layer using an 'expected_fingerprint' hash to detect content drift between preview and write was added, but it too defaults to None, meaning skipping it bypasses the check entirely rather than blocking the write. The developer concluded that both gaps share the same structural flaw: keyword-argument safety checks that only activate when the caller supplies the required evidence can be silently skipped by omission, not just by an explicit bypass.

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