Download email attachments to a managed server directory, returning path, size, and SHA256 hash. Files are not parsed or executed, ensuring safe retrieval.
下载原始附件到服务所在机器的受控目录，返回路径、大小、SHA256。不解析PDF/Word、不执行附件。
| Name | Required | Description | Default |
|---|---|---|---|
| account_id | Yes | ||
| message_id | Yes | ||
| attachment_id | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden and does meaningful work: it discloses the download destination (controlled directory), the returned metadata, and explicitly states that attachments are not parsed or executed. It does not cover authentication requirements, size limits, or failure modes, but the core safety and storage behavior is transparent.
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 compact sentences with no filler. It front-loads the action and output, then adds the important safety caveats. Every clause 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?
For a simple three-parameter download tool with no output schema and no annotations, the description covers the key contract: what is downloaded, where it goes, what is returned, and what is not done. It is slightly incomplete regarding error behavior and how to obtain the required IDs, but these are minor gaps for this 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?
The schema has 0% description coverage and the description provides no additional meaning for account_id, message_id, or attachment_id. The agent must rely on parameter names alone; the description does not compensate for the missing parameter documentation.
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 (download raw attachment) and resource (attachment on server), plus the output contract (path, size, SHA256). It distinguishes itself from siblings like mail_get_message and mail_export_message by emphasizing raw download and non-parsing/non-execution behavior.
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 does not explicitly state when to use this tool versus alternatives, nor does it mention exclusions. The safety-related notes (no parsing/execution) imply a use case, but the tool never routes the agent to siblings like mail_export_message or mail_get_message for other scenarios.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.