gmail_get_messageRetrieves a Gmail message's headers, plain-text body, and attachment metadata by message ID, with a size-capped body and no attachment downloads.
Get one message: headers, plain-text body (size-capped), and attachment metadata.
Attachment contents are not downloaded.
| Name | Required | Description | Default |
|---|---|---|---|
| message_id | Yes | ||
| max_body_chars | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already declare readOnly, idempotent, non-destructive, and open-world, so the safety profile is covered. The description adds genuinely non-obvious behavior: the body is size-capped and attachment contents are not downloaded, which directly prevents an agent from assuming it has full message or attachment data.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two short sentences, front-loaded with what is returned and followed by the single most important limitation. Nothing is repeated from the schema or annotations and nothing is wasted.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With an output schema present and annotations covering safety, the description only needs to fill behavioral gaps, which it largely does via the body cap and attachment caveat. Minor gaps remain: no mention of what happens for HTML-only messages or on an invalid message_id.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must carry the parameter burden. 'Plain-text body (size-capped)' hints that max_body_chars truncates the body, but the parameter is never named, no units or truncation-indicator behavior is described, and message_id is left entirely to the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description uses a specific verb and resource ('Get one message') and enumerates exactly what is returned: headers, plain-text body, and attachment metadata. The scope word 'one' implicitly separates it from gmail_get_thread and gmail_search_messages, but no sibling is named explicitly.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
Usage is only implied: the tool is for fetching a single message, presumably when you already have a message_id. There is no statement of when to prefer this over gmail_get_thread (full conversation) or gmail_search_messages (unknown id), and no prerequisites or exclusions are given.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.