megabytespace

Audit MCP Error Semantics — Security skill for Claude Code

Security community

Catch Resend-class bug (isError: false on HTTP 4xx/5xx) across all MCP server tool handlers.

How to install Audit MCP Error Semantics

Installs to ~/.claude/skills/megabytespace-claude-skills-audit-mcp-error-semantics/SKILL.md

Terminal
mkdir -p ~/.claude/skills/megabytespace-claude-skills-audit-mcp-error-semantics && curl -fsSL https://raw.githubusercontent.com/megabytespace/claude-skills/HEAD/commands/audit-mcp-error-semantics.md -o ~/.claude/skills/megabytespace-claude-skills-audit-mcp-error-semantics/SKILL.md

Restart Claude Code, or start a new session, for it to be picked up.

What Audit MCP Error Semantics does

description: Catch Resend-class bug (isError: false on HTTP 4xx/5xx) across all MCP server tool handlers argument-hint: [--server=] [--fix]

Audit every MCP server tool handler for the silent-failure anti-pattern: `fetch()` calls that return HTTP 4xx/5xx but still resolve `isError: false`, so Claude reads a garbage success instead of

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Full documentation available on GitHub

View Source Repository

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