download_message_attachment

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

The annotations (readOnlyHint=true, idempotentHint=true, destructiveHint=false) already declare the safety profile; the description adds only the detail that the file is placed in a 'private local directory', which is marginally useful. It does not describe behavior on missing attachments, overwrites, or exact local path conventions. This does not contradict the annotations (read-only on the server is compatible with saving a local copy).

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 short sentence that correctly places the core action first. No filler, no redundancy, and the most important fact (download + target location) is front-loaded.

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?

No output schema is present, and the description does not say what the result is (e.g., a local file path, success status, or the downloaded file itself). It also does not give any hint about how to obtain the required IDs from the sibling tools, leaving the caller to infer the entire workflow.

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?

Only student_id has a schema description, and the description adds nothing about message_id or attachment_id – where they come from, how they are formatted, or how they relate to the message. At 33% schema description coverage, the description must 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 specifies a concrete action (

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 when to use or when-not guidance exists. The tool relies on the caller having a student_id, message_id, and attachment_id, but the description never references the sibling tools (list_messages, get_message, list_students) for obtaining those IDs, nor does it explain why one would use this downloader rather than just reading the message directly.

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