Himalaya MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states that 'Attachments are saved to the current working directory,' which adds useful context about file system impact. However, it lacks details on permissions needed, error handling, rate limits, or what happens if attachments are large or numerous. For a tool that writes files, this is a significant gap in transparency.

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 well-structured and appropriately sized. It starts with the core purpose, adds behavioral context in the second sentence, and lists parameters with brief explanations. Each sentence earns its place, and it's front-loaded with the main action. A minor deduction for slightly verbose parameter formatting, but overall efficient.

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 with 0% schema coverage and no annotations, the description provides basic parameter semantics and some behavioral context (file saving location). An output schema exists, so return values don't need explanation. However, for a tool that downloads files, more details on file naming, overwrite behavior, or error cases would improve completeness. It's minimally viable but has clear gaps.

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 0%, so the description must compensate. It provides brief explanations for each parameter: 'envelope_id: The envelope/message ID,' 'folder: Folder name. Defaults to INBOX,' and 'account: Account name. If omitted, uses the default account.' This adds basic meaning beyond the schema's titles, but doesn't cover formats, constraints, or examples. With 3 parameters and low schema coverage, this is adequate but minimal.

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 the tool's purpose: 'Download all attachments from a message.' It specifies the verb ('download') and resource ('attachments from a message'), making it easy to understand what the tool does. However, it doesn't explicitly differentiate from sibling tools like 'message_read' or 'envelope_list', which might also involve message operations, so it doesn't reach a perfect score.

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 provides no guidance on when to use this tool versus alternatives. It mentions parameters like 'folder' and 'account' with defaults, but doesn't explain scenarios where you'd choose this over other tools (e.g., 'message_read' for viewing content without downloading). There's no mention of prerequisites or exclusions, leaving usage context implied at best.

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