get_mail_message

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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds context about what the complete message includes, but it does not disclose potential failure modes, permission requirements, or body-size limitations, which would add meaningful behavioral transparency 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 organized clearly into summary, Args, and Returns sectionsaisfront-loaded with the core action and avoids bloat. Some redundancy exists between the opening sentence and the second paragraph, both stating that the complete message is retrieved, which costs a point.

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 single required integer parameter, the presence of an output schema, and strong safety annotations, the description provides enough information for an agent to invoke the tool correctly. It specifies how to find the ID and what the response includes; missing error-handling details are a minor gap for a simple read operation.

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 compensate for the undocumented message_id parameter. It does so effectively by clarifying that the parameter is the message database ID, not the email Message-ID header, and by specifying exactly how to obtain it via list_mail_messages.

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 clearly states a specific action ('Get a full email message including its body') and enumerates the returned components: body text, ID, tags, and attachment metadata. It does not explicitly distinguish itself from the closely named sibling get_messages beyond the singular focus and the reference to list_mail_messages, so it stops just short of a 5.

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 practical context by directing the agent to use list_mail_messages to find message_id, which is useful routing guidance for parameter acquisition. However, it does not state when to choose this tool over alternatives like get_messages, send_mail, or move_mail_message, nor does it mention any exclusions.

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