Dialpad MCP server

dialpad_send_sms

Send a text message to a Dialpad channel or up to 10 phone numbers, with sender set by number, user, or group and administrator approval before sending.

Instructions

Send a text message, either to a Dialpad channel (channel_hashtag, as the N8N alerts do) or to up to 10 phone numbers. The sender is from_number, user_id or a sender group. Proposal: an administrator must approve it before it is sent.

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": {
      "text": "<text>"
    },
    "name": "dialpad_send_sms"
  }
}

Input Schema

Name	Required	Description
`text`	Yes	Message text.
`user_id`	No	Send as this user.
`to_numbers`	No	Recipient numbers in E.164 format (up to 10).
`from_number`	No	Sending number (must belong to a user or group in Dialpad). Overrides user_id and sender group.
`channel_hashtag`	No	Dialpad channel to post to, e.g. n8n.
`sender_group_id`	No	Send as this office, department or call center. Needs sender_group_type.
`sender_group_type`	No	Type of sender_group_id.
`infer_country_code`	No	Accept numbers without a country code, using the sender's country.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 14, 2026

TDQS

A3.5/5.0

Behavior3/5

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

Annotations already declare this is a non-readonly, non-idempotent, non-destructive open-world write, so the safety profile is known. The description adds the recipient cap (10 numbers) and the sender-precedence model, but the sentence 'Proposal: an administrator must approve it before it is sent' is unclear — it is not stated whether approval is always required, only for certain senders, or merely a proposed feature — which weakens rather than strengthens disclosure.

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

Conciseness4/5

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

Three tight sentences with the core action and the channel-vs-numbers split front-loaded, followed by sender options. The final approval sentence is awkwardly worded ('Proposal:') and could be rewritten or removed, which is the only real waste.

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

Completeness4/5

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

For an 8-parameter mutation with full schema coverage and annotations present, the description covers the key decisions an agent must make: destination type and sender identity. It does not describe what the call returns or any rate/approval mechanics, but with no output schema and rich annotations the remaining gap is small — the ambiguous approval clause is the main incompleteness.

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 schema already documents every parameter, including that from_number overrides user_id and sender group. The description adds a useful mental model by grouping the sender options (from_number / user_id / sender group) and giving a channel_hashtag example ('as the N8N alerts do'), but it repeats rather than extends the schema's parameter documentation, so the baseline 3 applies.

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

Purpose4/5

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

The description uses a specific verb and resource ('Send a text message') and immediately enumerates the two delivery targets: a Dialpad channel via channel_hashtag or up to 10 phone numbers. That is enough for an agent to know exactly what the tool does. It stops short of a 5 only because no sibling differentiation is needed or offered (no other SMS tool exists), so there is nothing extra to distinguish.

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?

It conveys the two usage modes and the sender-selection options (from_number, user_id, or a sender group), which implies when to pick each. However, there is no explicit when-not-to-use guidance, no mention of prerequisites such as verified numbers or channel membership, and the approval sentence is too ambiguous to function as a usage rule.

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