gmail_read_message

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

No annotations are provided, so the description carries the full burden of disclosing behavior. It only says 'Read one Gmail message' and does not describe whether attachments are included, what the response contains, error conditions, or authentication requirements. The read-only nature is implied by the verb but not explicitly stated in a useful way.

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, efficient sentence with no redundancy. It is front-loaded with the core action and resource, making it easy to scan and understand.

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 no output schema and no annotations, the description should explain what the tool returns and how to invoke it correctly. It does neither, and the missing messageId semantics plus lack of usage guidance leave a meaningful gap for an agent trying to use this tool reliably.

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 only 50%: 'account' is described, but 'messageId' has no schema description. The tool description does not compensate by explaining how to obtain a messageId or what format it should take. An agent receives minimal guidance beyond the parameter names.

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 clear action ('Read') and a specific resource ('one Gmail message'), which distinguishes it from the sibling 'gmail_read_thread' by explicitly focusing on a single message rather than a thread. It is unambiguous and directly reflects the tool's function.

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 no indication of when to use this tool over alternatives like gmail_search or gmail_read_thread. It does not mention prerequisites, such as needing a message ID from a prior search, nor does it explain what distinguishes this tool from its siblings.

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