Download File

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

The description goes beyond the read-only annotation by explaining how text files are returned as readable text, binary files as base64, and that files over 10 MB are refused. These are important behavioral details not covered by annotations.

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 concise, with the main purpose stated first, followed by file type handling and size limit. It is well-structured and easy to read without unnecessary verbosity.

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 core functionality, return types, and size constraint. It lacks details on error cases (e.g., file not found), but for a simple download tool, this is fairly complete. No output schema exists, so the return behavior description suffices.

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 already provides clear descriptions for file_id and course_id. The description adds little extra meaning, mostly repeating 'by ID'. Since schema coverage is 100%, the baseline of 3 is appropriate.

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 that the tool downloads the content of a Canvas file by ID. It distinguishes itself from sibling tools that list or get file metadata by focusing on content retrieval.

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 mention when to use this tool over alternatives like get_file or list_files. It implies usage for downloading actual file content, but lacks explicit guidance or examples.

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