Download Audio

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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so the description does not need to repeat that. It adds that the tool uses yt-dlp and returns a path, which is useful. However, it does not disclose behaviors like overwriting files, creating directories, or network dependencies, so some transparency gaps remain.

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 three sentences long, with no fluff. It front-loads the main purpose, then states the return value and underlying library. Every sentence earns its place.

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 the simple tool, the description covers essentials: what it does, what it returns, and how it works. The schema covers parameter defaults, and annotations indicate side effects. It does not mention potential errors or the need for check_dependencies, but these are not critical for a basic download tool.

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 100%: each parameter has a meaningful description (e.g., url is any yt-dlp supported URL, filename defaults to video title, output_dir defaults to system temp). The tool description itself adds no additional parameter semantics, so baseline 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 the tool's purpose: 'Download only the audio from a URL as MP3.' This is a specific verb+resource combination that distinguishes it from the sibling tool download_video. It also mentions the output (path to downloaded file), making the purpose unambiguous.

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 clear context: this tool is for downloading audio only, implying it should be used when audio is needed. It does not explicitly mention alternatives or exclusions, but the phrase 'Download only the audio' and the sibling context (download_video) imply a usage boundary.

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