Gmail MCP Server

by neutral-Stage

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TypeScript

Local

modify_email

Add or remove labels, mark as read/unread, archive, or trash a Gmail message using its ID.

Instructions

Modify a single email: add/remove labels, mark as read/unread, archive, or move to trash.

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": {
      "id": "<id>"
    },
    "name": "modify_email"
  }
}

Input Schema

Name	Required	Description
`id`	Yes	Gmail message ID
`addLabelIds`	No	Label IDs to add (e.g. 'STARRED', 'IMPORTANT', or custom label ID)
`removeLabelIds`	No	Label IDs to remove (e.g. 'UNREAD', 'INBOX')

Schema Changelog

Changes observed during successful MCP inspections.

First observedv2.0.0Jun 21, 2026

TDQS

B3.4/5.0

Behavior3/5

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

The description implies a write operation and lists actions, but does not disclose side effects (e.g., reversibility, notification behavior) or explain that marking as read/unread and archiving are achieved via label manipulation. With no annotations, the description carries the burden but only partially addresses it.

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?

Single sentence that is front-loaded with the action and immediately conveys the tool's purpose. Every phrase earns its place with no unnecessary words.

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?

The description covers the main operations for a single email modification tool. It lacks explanation of how operations map to label IDs but remains adequate given the schema's clarity. No output schema is provided, but that is acceptable for a mutation tool.

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% and parameters are well-described with examples. The description adds value by enumerating high-level actions (mark as read/unread, archive, trash) but does not explicitly map them to label IDs, so it provides moderate additional meaning.

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 clearly states the verb 'modify' and resource 'single email', listing specific operations like add/remove labels, mark as read/unread, archive, or move to trash. It distinguishes from batch tools and specific operations like trash_email, but does not explicitly differentiate from all siblings.

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 versus alternatives. It does not mention that for moving to trash, a dedicated tool exists, or when to prefer batch_modify_emails. The agent receives no usage context.

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