Get Gmail Message

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

Annotations already declare this as read-only, idempotent, and non-destructive. The description adds value beyond these by specifying the return behavior: 'Full message content including headers and body text' and the default response_format. This is useful since no output schema exists. It does not contradict the annotations.

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 compact and well-structured: a one-sentence summary, a clear Args list, and a Returns line. Every sentence is informative and there is no redundant filler. It is front-loaded with the tool's core purpose.

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 two-parameter read tool with comprehensive annotations and full schema coverage, the description is sufficient. It clearly conveys input and output. It could be slightly more complete by noting how this differs from thread retrieval or mentioning attachments, but these are not essential for correct tool invocation.

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 100%, so the schema already fully documents both parameters. The description essentially repeats the schema ('message ID to retrieve', output format options) without adding extra meaning. Baseline of 3 is appropriate because the description provides no additional parameter insights.

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 states a specific verb ('Get') and resource ('full content of a specific Gmail message'), making the tool's purpose immediately clear. It distinguishes itself from sibling tools like gmail_list_messages (which lists summaries) and gmail_get_thread (which retrieves a thread) by focusing on a single message's full content.

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 you have a message ID and need the full content, but it does not explicitly state when to prefer this over gmail_get_thread or gmail_list_messages. No alternatives or exclusions are mentioned, so the guidance is only implied rather than explicit.

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