Missive MCP

missive_create_contacts

Create one or more contacts with names, contact info (email, phone, address), and memberships to groups or organizations.

Instructions

Create one or more contacts. Body shape { contacts: [...] }. Each contact's contact_book falls back to MISSIVE_DEFAULT_CONTACT_BOOK. Supports names, starred, gender, infos[] (emails/phones/socials/addresses/custom), and memberships[] (organizations/groups).

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": {
      "contacts": "<contacts>"
    },
    "name": "missive_create_contacts"
  }
}

Input Schema

Name	Required	Description	Default
`contacts`	Yes	One or more contacts to create.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jun 26, 2026

TDQS

A4.3/5.0

Behavior4/5

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

Annotations already declare destructiveHint: false, indicating non-destructive. The description adds useful behavioral details: the default contact_book fallback and supported subfields (starred, gender, infos, memberships). It does not discuss rate limits or auth, but the annotations reduce the burden.

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?

Two efficient sentences cover the core purpose, key behaviors, and parameter hints. No wasted words; front-loaded with the primary action.

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?

The description is thorough for input details, but it does not mention what the tool returns (e.g., the created contacts or IDs). Since there is no output schema, the description has a gap. A complete description would at least indicate the return type.

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

Parameters4/5

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

Schema coverage is 100%, so the schema documents the contacts array. The description adds meaning beyond the schema by explaining the body shape, the default contact_book, and listing supported subfields (infos types, memberships). This helps the agent understand the structure without reading every property.

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 'Create one or more contacts,' a specific action on a specific resource. It distinguishes from siblings like missive_get_contact, missive_update_contacts, etc., by focusing on creation.

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

Usage Guidelines4/5

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

The description implies when to use this tool (for creating contacts), but lacks explicit guidance on when not to use it or alternatives. However, the sibling tool names provide context for choosing between create and update operations.

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

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