google-workspace-mcp

gmail_read_thread

Retrieve all messages in a Gmail thread using its thread ID. Get a complete view of a conversation in a single call.

Instructions

Read all messages in a Gmail thread by its thread ID.

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": {
      "thread_id": "<thread_id>"
    },
    "name": "gmail_read_thread"
  }
}

Input Schema

Name	Required	Description	Default
`thread_id`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 2, 2026

TDQS

A3.6/5.0

Behavior3/5

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

With no annotations provided, the description carries the full burden. It clearly indicates a read-only operation ('Read') but does not disclose any potential side effects, such as whether messages are marked as read, or what happens if the thread ID is invalid. For a read operation, this is acceptable but could be more explicit.

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 with no filler or redundant information. It is concise and front-loaded, covering the essential purpose efficiently.

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?

Given the tool's simplicity (one parameter, no annotations, output schema exists), the description provides the basic purpose but lacks context about when to choose this over gmail_read_message or gmail_search. It does not mention any prerequisites or limitations, making it a minimal but adequate description for a straightforward read operation.

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

Parameters2/5

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

Schema coverage is 0%, so the description must compensate. However, it only repeats the parameter name ('by its thread ID') and adds no new meaning about the format, origin, or usage of the thread_id. The parameter title in the schema already says 'Thread Id', so the description provides no additional value.

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 uses a specific verb ('Read') and resource ('Gmail thread'), and clearly distinguishes from sibling tools like gmail_read_message by specifying 'all messages in a thread' versus a single message. This makes the tool's purpose unambiguous.

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 implies the usage context (when you need all messages in a thread) but does not explicitly mention when not to use it or name alternative tools. The phrase 'all messages' hints at the distinction from single-message tools, but no explicit exclusions or alternatives are provided.

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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