Get Gmail Message Content

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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description adds substantial behavioral detail: 20,000-character truncation, export-to-disk with a short-lived download URL or file path, and stateless inline fallback. These details help the agent anticipate response size and transport behavior, going well beyond 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 three tightly written paragraphs: a one-sentence purpose statement, a concise explanation of truncation and full=True behavior, and a short note on stateless deployments. Every sentence contributes new information and is front-loaded with the most important details.

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?

Given the strong annotations, complete input schema with 100% parameter coverage, and presence of an output schema, the description covers all key operational edge cases: truncation, full=True behavior, transport differences, and stateless mode. It is fully sufficient for reliable 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%, and the schema itself has rich parameter descriptions. The tool description adds extra value by explaining the 20,000-character truncation threshold and the rationale that large messages never stream through model context, which complements the schema's full=True description.

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 opens with 'Retrieves the full content (subject, sender, recipients, body) of a specific Gmail message,' using a specific verb and clearly identifying the resource and scope. The 'specific' qualifier distinguishes it from sibling batch/thread/attachment tools.

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 gives clear context on when to use full=True (large messages, byte-exact fidelity) and when the default truncated inline body is used. It does not explicitly name sibling alternatives or state when not to use this tool, so it lacks explicit exclusion guidance but is otherwise clear.

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