Email Get Message

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds useful behavioral context beyond annotations by specifying the exact return composition and the attachment metadata shape, helping the agent understand what the tool actually produces.

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 two tight sentences with no filler. The primary purpose and return fields are front-loaded, and the attachment note is placed second as a natural follow-up. Every sentence earns its place.

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 rich input schema, output schema, and strong annotations, the description is largely complete for a read-only single-message fetch. It covers the main return contents and points to the correct sibling for attachment downloads. It could be slightly stronger by explicitly contrasting with email_get_messages, but nothing critical is missing for correct 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 input schema already fully documents all four parameters and their defaults. The description adds no additional parameter-level semantics, but it does not need to; the baseline of 3 applies because the schema carries the burden.

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 and resource: "Get one message" and enumerates the exact returned fields (headers, flags, body_text, attachments list). It clearly distinguishes itself from the sibling email_get_messages by emphasizing "one message," and from email_get_attachment by describing attachments as metadata only.

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 single-message retrieval and explicitly directs attachment downloads to email_get_attachment. However, it does not state when to prefer this tool over email_get_messages, email_list_messages, or email_search, nor does it provide exclusion criteria. Usage context is mostly 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.