Fetch a video transcript (captions)

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

With no annotations, the description discloses key behaviors: reads existing captions, requires yt-dlp helper, and provides installation instructions. It could be improved by mentioning error scenarios or authorization, but overall transparent.

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 (4 sentences) and front-loaded with the main purpose. Each sentence adds distinct value without fluff.

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 tool has 4 parameters and no output schema, the description covers essential aspects: core function, parameter guidance, limitations, and prerequisites. It could mention the return format, but it is still sufficient for an agent.

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 coverage is 100%, but the description adds significant value by enumerating accepted YouTube URL formats (watch, youtu.be, shorts, embed, live) and explaining the installYtDlp parameter in context. This goes beyond the schema descriptions.

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 explicitly states it fetches a transcript from published captions, specifies supported YouTube URL formats, and clarifies it does not transcribe audio or support Twitch. This clearly distinguishes it from siblings.

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 for when to use the tool (fetch existing transcript) and when not (Twitch, no audio transcription). It also instructs on installing yt-dlp if needed. However, it does not explicitly compare to other eql tools for transcript retrieval.

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