get_transcript

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

With no annotations, the description carries full burden. It discloses key behaviors: does not transcribe audio, only returns existing captions, default language is ["en"], include_timestamps groups into ~15s blocks with [mm:ss] prefix, and translate_to performs translation. It does not mention error handling (e.g., missing video) or side effects, but for a read-only tool, the covered traits are sufficient.

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 well-structured with a concise opening sentence, a clarifying limitation, then parameter details in a list-like format, and finally return type. It is front-loaded. While every sentence is valuable, the length could be slightly reduced without losing clarity, but overall it is efficient.

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 4 parameters, no output schema, and no annotations, the description is fairly complete. It explains the return (plain text), all parameters, and key behavior. It could add more on error scenarios (e.g., no captions found returns empty string or error), but for typical use it is adequate.

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 0%, so the description must fully explain each parameter. It does so: video (YouTube URL/ID format), languages (priority order, default ["en"]), include_timestamps (purpose and format), translate_to (optional ISO code). The description adds critical meaning beyond the schema's minimal title/type fields.

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 it fetches existing YouTube captions as text, explicitly distinguishes itself from audio transcription ("it does not transcribe audio"), and the verb "Fetch" plus resource "YouTube video's existing captions" is specific. This differentiates it from sibling tools like list_transcripts (which lists available captions) and get_video_metadata (metadata).

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: use this tool to get existing captions to answer questions about a video. It also clarifies a limitation (only works if captions exist). However, it does not explicitly state when not to use it or suggest alternative sibling tools (e.g., use list_transcripts to check availability first, or get_video_metadata for non-caption info).

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