"How to create draft emails using Gmail's support agent class" matching MCP connectors:

Generate synthetic random user data for testing, demos, and development without using real persona.

Simulate, test, and analyze cloud architectures without deploying real infrastructure. Cloud World Model enables AI agents to model cloud environments, evaluate architecture behavior and costs, run failure and chaos simulations, and explore infrastructure scenarios across cloud providers.

Moderated usability testing: read sessions, notes, transcripts, reports, and draft test scenarios.

Free platform to test MCP clients without installing anything. Create mock tools with dynamic templates, configurable delays, conditions (if/then), and response sequences. Supports JSON-RPC 2.0 over Streamable HTTP. Built-in text_echo and json_echo tools. Rate-limited tiers: anonymous (5 calls/min, 1 mock tool), registered (10 calls/min, 4 mock tools), premium (60 calls/min, unlimited). Zero setup — no install, no registration required. More info: https://www.testmcp.dev

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.

Testing, benchmarking and auditing autonomous AI agents — methods, harnesses, evidence

Point Claude Code, Qwen Code, Cursor, or any MCP client at https://docs.jmeter.ai/api/mcp and your agent answers JMeter questions grounded in this documentation, with a source link for every answer. Free, no API key, no signup.

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.

Scan any website or MCP server for agent readiness: 0-100 score, a fix per failing check. Free.

Give AI coding agents access to your Vynix visual feedback, bug reports, and AI diagnosis.

49 deterministic tools for text integrity, agent control, and contextual quality evidence.

AgentReady.market audit: can an AI shopping agent find, understand and BUY on this store? /100.

Exposes FEDLIN's public security scanners as agent-callable tools over Streamable HTTP.

Preflight QA for AI-agent deliverables with structured verdicts and repair guidance.

Deterministic JSON checks with signed evidence and x402-paid execution

Verifies AI agent work end to end: real artifacts and outcomes checked, not self-reported success.

Grade MCP servers A to F with the open behavioral litmus. npm: full toolset; hosted: lookups only.

Check if your MCP server is ready to publish on the MCP Registry, Smithery, or npm.

Generate realistic relational test data — 156 field types, 22 locales, JSON/CSV/SQL, free previews.

Read-only MCP server for the OPERANT AI operating-agent calibration benchmark.