Extract a YouTube transcript

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

With no annotations, the description fully discloses costs (credit tiers based on length), caching behavior (30 days free for cached extracts), and return content (title, channel, duration, language, transcript with clickable timestamps). No contradictions.

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?

Every sentence is useful: purpose, usage, costs, caching, return structure. No redundancy or fluff. Well-organized into clear paragraphs.

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 no output schema, the description adequately explains what is returned (title, channel, duration, language, transcript with clickable timestamps). Parameter descriptions are covered in schema. No gaps.

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%. The description adds extra context to the url parameter with examples (youtube.com/watch?v=…, youtu.be/…, or shorts) and to lang with BCP-47 examples and default. This goes beyond the schema's format and pattern constraints.

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 pulls a YouTube transcript and returns it as Markdown with timestamps. It uses a specific verb+resource and distinguishes from sibling tools (get_related_videos, get_video_metadata, search_videos) which perform different functions.

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 explicitly says 'Use this whenever the user provides a YouTube URL and wants to summarise, quote, search, or otherwise process the video's spoken content.' It does not directly mention when not to use or compare to alternatives, but the use case is clearly defined and siblings are unrelated.

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