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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds only that the return is the 'full raw MIME message'; it does not disclose size limits, encoding behavior, header inclusion, or other operational traits 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?

A single sentence that is front-loaded with the tool's purpose and contains no wasted words. It is appropriately sized for a simple getter.

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?

The tool is simple, the single parameter is fully documented, and annotations cover the safety profile. Still, without an output schema, the description could do more to explain what an agent receives and how this raw MIME retrieval differs from sibling retrieval tools.

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?

The schema has 100% description coverage for the single 'id' parameter, including the 'em_xxx' format. The description does not add parameter meaning beyond what the schema already provides, which is acceptable baseline behavior when schema coverage is high.

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 gives a specific verb and resource: 'Return the full raw MIME message of an email.' It is clearer than a bare getter because it specifies the raw MIME format. However, it does not distinguish this tool from close siblings like get-email, get-email-body, get-email-meta, or get-email-attachments.

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 offers no explicit guidance on when to use this tool versus get-email-body, get-email-meta, or get-email. An agent can infer that 'raw MIME' is for raw source access, but there are no stated conditions, exclusions, or alternatives.

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