Twilio alternatives
The highest-scoring alternative to Twilio is Telnyx at 91/100 on the AgentReady, against 47/100 for Twilio.
All scored in SMS, Voice & Communications.
What Telnyx does that Twilio does not
Telnyx passes llms-full.txt / full agent docs, mcp discoverable, openapi / spec quality, authentication documented, pricing understandable, request examples provided, response examples provided, errors and status codes documented, limits / constraints documented, self-service signup, programmatic credential creation, free trial or free allowance, mcp integration available, structured, predictable output, machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable, agent compatibility verified, and Twilio fails them. That is the whole of the gap between the two scores, so if none of those matter to your agent the ranking above overstates the difference.
Why people look for an alternative
Twilio fails llms-full.txt / full agent docs, mcp discoverable, openapi / spec quality, authentication documented, pricing understandable, request examples provided, response examples provided, errors and status codes documented, limits / constraints documented, self-service signup, no mandatory sales call, programmatic credential creation, free trial or free allowance, fast time to first request, mcp integration available, structured, predictable output, machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable, agent compatibility verified. Each one is a place an unattended run stops, which is usually what sends someone looking in the first place.
What this category actually supports
Across the 15 products scored in SMS, Voice & Communications, send sms is offered by 60%, send whatsapp is offered by 47%, make a voice call is offered by 40%, provision a phone number is offered by 33%. Anything under half is a gap you should expect to fill yourself whichever one you pick.
An agent can get this list directly: resolve("alternative to Twilio") over the MCP server, or GET /v1/categories/communications.