extract_chapters

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains the source ('description') and the return shape (chapter list with titles and start times), which is useful. However, it does not disclose behaviors around missing chapters, parsing failures, or rate limiting. There is no contradiction with any annotations since none exist.

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, tightly worded sentence that states the action, source, and output with no filler. Key information is front-loaded and every word 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?

For a single-parameter, no-output-schema tool, the description gives the essential input and output information. It states that results come from the video description and returns chapter titles with start times. It could be more explicit about edge cases like missing chapters, but overall it is sufficiently complete for the tool's simplicity.

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%, as the only parameter 'url' is documented with 'YouTube video URL or video ID'. The description does not add additional semantic detail beyond the schema, which is acceptable given complete schema coverage. 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 uses a specific verb ('Extract'), identifies the exact resource ('chapter timestamps from a YouTube video's description'), and states the output ('structured chapter list with titles and start times'). This clearly distinguishes it from sibling tools like get_transcript or get_video_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 implies when to use the tool: when chapter timestamps are needed from a video's description. However, it does not explicitly state exclusions or alternatives, such as using get_video_metadata or get_transcript for other types of video information.

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