"Managing Gmail Account" matching MCP connectors:

Check that your AI is being logical. Free tool that mathematically catches contradictions in agent reasoning. No account needed. Also offers paid guardrails that converts natural language to formal verification proofs, that anyone can check succinctly.

Risk-scan a diff, flag AI-generated-code tells, find secrets. 5 of 7 tools need no account.

The OpenZeppelin Solidity Contracts MCP server integrates OpenZeppelin's security and style rules into AI-driven development workflows, enabling AI assistants to generate safe, correct, and production-ready smart contracts. It automatically validates generated code against OpenZeppelin standards (including imports, modifiers, naming conventions, and security checks) and supports various contract types including ERC-20, ERC-721, ERC-1155, Stablecoins, RWA, Governor, and Account contracts through prompt-driven workflows.

Pre-flight check for AI coding agents: hallucinated packages + secrets, 6 ecosystems, no account.

A fully free linter for agent skill files: lint_skill validates YAML frontmatter, structure, size budgets, and safety phrasing with a pass/fail verdict; packaging_check validates zip layout against marketplace rules; plus regex_test, json_validate, diff_texts, and cron_explain for skill authors. No license or account required.