gmail_read_message

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

No annotations are provided, so the description must disclose behavior. It states 'Read' which implies a non-mutating operation, but it does not specify what 'full content' includes (e.g., attachments, headers) or any potential side effects like marking as read. This leaves ambiguity.

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?

The description is a single concise sentence that front-loads the verb and resource, with no wasted words.

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?

For a simple tool with one parameter and an output schema, the description is mostly adequate, but it lacks important context about the scope of 'full content' (e.g., whether attachments are included), which is relevant given sibling tools like gmail_get_attachment.

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?

The only parameter message_id is mentioned as 'by its ID', but the description does not provide details on ID format, how to obtain it, or validate it. With 0% schema description coverage, this is insufficient.

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 the specific verb 'Read' with the resource 'full content of a Gmail message by its ID', clearly indicating a read operation on a specific message. It implicitly differentiates from siblings like gmail_read_thread and gmail_search by focusing on full content of a single message.

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?

The description implies usage when a message ID is available and full content is needed, but it does not explicitly state alternatives or exclude other tools. No guidance on when to prefer this over gmail_search or gmail_read_thread.

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