download_file

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

With no annotations, the description carries the burden of disclosure. It explains that the file is downloaded to a temporary local path and returns that path for reading/viewing. This covers key behavioral aspects, though it doesn't detail cleanup, failure modes, or file type handling.

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 compact and well-structured. The first sentence states the purpose and result, and the second provides the parameter detail. No unnecessary words or redundant information.

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 tool is simple with one parameter and an output schema present. The description explains the return value and use case. It could mention edge cases like non-existent URLs or authentication, but for the tool's complexity it is sufficiently complete.

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 input schema only names the parameter, but the description provides a clear definition and example ('The Ed CDN URL, e.g., https://static.au.edusercontent.com/files/...'), which fully compensates for the 0% schema coverage.

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 a file'), a specific resource ('Ed Discussion CDN URL'), and the output ('local file path'). This distinguishes it from sibling tools like upload_file and download_thread_files by specifying the source and destination.

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 implies usage: when you have a CDN URL and need to read/view the file locally. However, it does not explicitly mention when to avoid this tool or compare it to alternatives like download_thread_files, so guidance is implied rather than direct.

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