get_raw_message

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

With no annotations, the description carries the full burden. It discloses the main side effect: raw bytes are written to 'out' and a {path, bytes_written} result is returned. However, it does not disclose overwrite behavior, error cases, or system-level effects like file replacement or permission requirements.

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 short and front-loaded, with the main purpose in the first sentence and the return contract in the second. Both sentences carry useful information, though the first sentence has a minor grammatical issue that slightly undermines polish.

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 description covers the primary file-writing behavior and return shape, and an output schema is noted as present. It remains incomplete as a standalone guide: message_id semantics and failure/overwrite behavior are absent, so an agent may still face edge-case ambiguity when invoking the tool.

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% and the description adds little for the undocumented message_id parameter. It mentions that bytes are written to 'out', but that parameter already has a schema description. message_id is never described in terms of format or source, leaving a gap that the description fails to fill.

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 and resource: fetch a message's full raw RFC822 MIME and write it to a local file path. It distinguishes from download_attachment by emphasizing the raw message rather than attachments, but it does not explicitly name the sibling or differentiate itself. The phrasing is also slightly awkward ('Fetch... to a local file path'), which slightly weakens clarity.

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?

There is no explicit guidance on when to use this tool versus download_attachment or other siblings. The phrase 'full raw RFC822 MIME' implies the intended use case, but no conditional direction or exclusions are provided. An agent must infer the distinction on its own.

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