Tool · Config lint

What does your MCP config actually allow?

A static lint for .mcp.json and claude_desktop_config.json: structural errors that stop servers from starting, and the risk patterns the MCP security guidance warns about - whole-disk filesystem scope, unpinned npx packages, tokens in plain text, remote servers on http. Runs entirely in your browser: the config never leaves the page, and redacted configs lint just as well.

Paste a .mcp.json or claude_desktop_config.json below, or load the file. The lint runs in this browser tab and the config is never sent anywhere. Redact real tokens first - the checks work on structure, not on secret values.

Load a .json file

Sources

MCP specification: Security Best Practices
Claude Code docs: Connect Claude Code to tools via MCP
MCP docs: Connect to local servers

What injected instructions can do with a reachable tool: Parameter poisoning and the AuthorityFlow defense. Lint the instructions you hand the agent with the CLAUDE.md linter, and check how its credentials are held with the credential check.