List YouTube Transcript Languages

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

With no annotations, the description must disclose behavior, but it only states the core action. It does not mention authentication requirements, read-only nature, error conditions (e.g., video has no captions), or output format.

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 a single concise sentence, using straightforward language with no redundant details. It earns its place by stating the tool's primary function without waste.

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 provides the core purpose but lacks usage context, exclusions, and output details. For a simple single-parameter tool with no annotations or output schema, it is minimally adequate but leaves the agent to guess about response format and prerequisites.

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 description mentions 'for a YouTube video', which implies the url parameter is the video URL, but it does not explicitly describe the parameter or its format. Since the schema has only one required parameter, this is sufficient for basic understanding, but it adds minimal value over the schema.

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 uses the specific verb 'Lists' and identifies the resource as 'creator and automatic caption tracks' for a YouTube video, making the tool's purpose immediately clear. It does not explicitly contrast with sibling tool youtube_get_transcript, but the distinction (listing vs. fetching) is implicit.

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 guidance is provided about when to use this tool versus alternatives like youtube_get_transcript. The description only states what it does, leaving the agent to infer that listing languages should precede fetching a transcript.

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