mcp-saas-toolkit

twilio_list_messages

Retrieve recent SMS messages with optional filters for phone numbers and date range. View message history including status and pricing.

Instructions

List recent SMS messages with optional filters. View sent and received message history with status and pricing.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "twilio_list_messages"
  }
}

Input Schema

Name	Required	Description
`to`	No	Filter by recipient phone number
`from`	No	Filter by sender phone number
`limit`	No	Number of messages to return (1-100). Default: 20
`date_sent_after`	No	Only include messages sent after this date (ISO 8601, e.g. 2024-01-01)
`date_sent_before`	No	Only include messages sent before this date (ISO 8601)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Jun 29, 2026

TDQS

B3.4/5.0

Behavior2/5

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

No annotations are provided, so the description must fully convey behavioral traits. It only states that it lists recent messages and includes status/pricing, but does not disclose side effects, rate limits, authentication requirements, or return format. For a read operation, this is minimal.

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 a single sentence of 15 words, front-loaded with the main action, and contains no unnecessary words.

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

Completeness2/5

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

Despite having 5 parameters, no required parameters, and no output schema, the description does not explain the return format, pagination behavior, or time range semantics. For a listing tool, more completeness is needed.

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 coverage is 100%, so the schema already documents all parameters. The description adds marginal value by saying 'optional filters' but does not provide additional meaning beyond what is in the schema. Baseline 3 is appropriate.

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 the verb 'List', resource 'SMS messages', and mentions the data included (status, pricing). It distinguishes from sibling tools like twilio_send_sms and twilio_make_call, which are write operations.

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

Usage Guidelines3/5

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

The description mentions 'optional filters' but provides no explicit guidance on when to use this tool versus alternatives like twilio_check_message_status. The usage context is implied but not explicit.

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