mcp-saas-toolkit

twilio_send_sms

Send an SMS message to any phone number using Twilio, with response including message SID, status, and price estimate.

Instructions

Send an SMS message via Twilio. Returns the message SID, status, and price estimate.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "to": "<to>",
      "body": "<body>"
    },
    "name": "twilio_send_sms"
  }
}

Input Schema

Name	Required	Description
`to`	Yes	Recipient phone number in E.164 format (e.g. +15551234567)
`body`	Yes	The text content of the SMS message (max 1600 characters)
`from`	No	Override the sender phone number. Defaults to TWILIO_PHONE_NUMBER env var.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Jun 29, 2026

TDQS

A3.5/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Since no annotations are provided, the description carries full burden. It mentions sending a message and returns, but does not disclose authentication requirements, potential costs, error handling, or asynchronous behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, front-loads the purpose, and contains no extraneous information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple tool, it adequately describes the action and return values, but lacks context on rate limits, cost implications, or when to use this over other messaging tools. No output schema, but return values are mentioned.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the description adds no extra value beyond the parameter descriptions already provided in the schema. Baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Send an SMS message via Twilio' and specifies the return values (SID, status, price estimate). It is distinct from sibling Twilio tools like twilio_check_message_status and twilio_make_call.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool vs. alternatives like email or Slack messaging. No prerequisites or exclusions mentioned.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.