download_attachment

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

Annotations already mark as readOnlyHint=true and destructiveHint=false. The description adds that the output is an embedded MCP resource, hinting at the return format. However, no behavioral details like size limits, supported file types, or authentication requirements are disclosed.

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 10-word sentence that is front-loaded with the verb and purpose. No extraneous information. Efficient and to the 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 3 parameters and no output schema, the description is too brief. It does not explain the return format beyond 'embedded MCP resource', which is helpful but insufficient. The tool is one of many email tools, but no cross-references or guidelines are provided.

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?

With only 33% schema description coverage, the description adds no information about the parameters. The accountId parameter is described in the schema, but messageId and attachmentId have no descriptions. The description should compensate but does not.

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 it downloads an email attachment as an embedded MCP resource. It uses a specific verb 'download' and specific resource 'email attachment', distinguishing it from sibling tools like get_email (which retrieves the email itself) or list_emails.

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?

No guidance on when to use this tool versus alternatives like get_email which might include attachment data. No prerequisites or restrictions mentioned. The description does not exclude any usage contexts.

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