Missive MCP

missive_update_responses

DestructiveIdempotent

Update existing canned reply templates by specifying changes to title, body, subject, recipients, labels, attachments, or external IDs. Each response requires its ID; omitted attributes remain unchanged.

Instructions

Updates one or more existing responses (canned reply templates). Provide one object per response, each with its id; only the attributes you include (title, body, subject, recipients, shared_labels, attachments, external IDs) are changed. Passing attachments replaces the whole set — omitted attachments are removed. Responses created by external integrations (e.g. WhatsApp templates) cannot be updated.

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": {
      "responses": "<responses>"
    },
    "name": "missive_update_responses"
  }
}

Input Schema

Name	Required	Description	Default
`responses`	Yes	The responses to update (at least one, each with its `id`).

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?

Disclosure beyond annotations: attachments replacement destroys omitted attachments, and external integration responses are immutable. Annotations provide idempotent and destructive hints, but description adds concrete behavioral details.

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?

Three sentences, front-loaded with main action, no fluff. Every sentence adds value.

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?

Covers update behavior, constraints, and attachment logic well. But no output schema and description does not mention return value or response format, leaving a gap for a mutation tool.

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?

With 100% schema coverage, description adds meaning: partial update semantics (only included attributes change) and attachment replacement behavior. Clearly explains how the responses array parameter works.

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?

Clearly states verb (update), resource (responses/canned reply templates), and scope (one or more by id). Distinguishes from create_responses sibling.

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?

Provides specific guidance: must include id per response, partial update behavior, attachment replacement warning, and explicit constraint that externally created responses cannot be updated. Lacks explicit when-to-use vs alternatives but is clear within its own context.

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

Deploy Server