usebouncer.com.
level 3: structured interaction
Bouncer is an email verification service. It helps users validate email addresses to improve data quality and email marketing ROI. You can use Bouncer to check the deliverability of email lists, identify invalid or risky email addresses, and prevent bounces.
LEVEL 1 /
BASIC ACCESSIBILITY
— 6/6
Uses semantic HTML elements (header, nav, main, article, section, footer) instead of just divs
PASS
Has proper meta tags (title, description, og:tags, twitter:card)
PASS
Includes Schema.org JSON-LD structured data
PASS
Does not block automated access with CAPTCHAs on public content
PASS
Content is server-side rendered (visible in HTML source, not just JS-rendered)
PASS
Uses clean, readable URLs (no excessive query params or hash fragments)
PASS
LEVEL 2 /
DISCOVERABILITY
— 5/6
Has a robots.txt that allows legitimate bot access
PASS
Provides an XML sitemap
PASS
Has a /llms.txt file describing the site for LLMs
PASS
Publishes an OpenAPI/Swagger specification for its API
FAIL
Has comprehensive, machine-readable documentation
PASS
Primary content is text-based (not locked in images/videos/PDFs)
PASS
LEVEL 3 /
STRUCTURED INTERACTION
— 4/6
Provides a structured REST or GraphQL API
PASS
API returns JSON responses with consistent schema
PASS
API supports search and filtering parameters
PASS
Has an A2A agent card at /.well-known/agent.json
FAIL
Rate limits are documented and return proper 429 responses with Retry-After
FAIL
API returns structured error responses with error codes and messages
PASS
LEVEL 4 /
AGENT INTEGRATION
— 3/6
Provides an MCP (Model Context Protocol) server
FAIL
Supports WebMCP for browser-based agent interaction
FAIL
API supports write operations (POST/PUT/PATCH/DELETE), not just reads
PASS
Supports agent-friendly authentication (API keys, OAuth client credentials)
PASS
Supports webhooks for event notifications
PASS
Write operations support idempotency keys
FAIL
LEVEL 5 /
AUTONOMOUS OPERATION
— 3/6
Supports event streaming (SSE, WebSockets) for real-time updates
PASS
Supports agent-to-agent capability negotiation
FAIL
Has a subscription/management API for agents
PASS
Supports multi-step workflow orchestration
PASS
Can proactively notify agents of relevant changes
FAIL
Supports cross-service handoff between agents
FAIL
SF Entry Point
https://usebouncer.com/llms.txt