youtube_analytics_retention

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

With no annotations provided, the description carries the burden of disclosing behavior. It explicitly states the output: 100 data points, percentage of viewers still watching, and relative retention compared to similar videos. This goes beyond the schema, though it does not mention authentication requirements or error behavior, which could be relevant given the sibling youtube_auth tool.

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 and well-structured: a one-sentence purpose statement, followed by a clear explanation of the return payload, then a list of arguments with formats and defaults. Every sentence provides value without fluff, and the most important information is front-loaded.

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's simplicity (3 params, no output schema), the description covers the core aspects: what it does, what it returns, and parameter details. It lacks information on prerequisites like authentication or how missing/invalid data is handled, but for a read-only analytics fetch, the description is largely sufficient and complete.

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 schema has 0% description coverage, but the description fully compensates by defining every parameter: video_id as 'YouTube video ID', start_date with format 'YYYY-MM-DD' and default of 28 days ago, and end_date with format and default of today. This adds essential meaning beyond the raw schema, which only lists names and types.

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 starts with 'Get audience retention curve for a specific video', which clearly states the action (get), the resource (audience retention curve), and the scope (specific video). This distinguishes it from sibling analytics tools like overview, top_videos, and video_detail, making its function unambiguous.

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 that this is for a specific video's retention data, which indicates when to use it. However, it does not explicitly mention when not to use it or point to alternative tools, such as youtube_analytics_video_detail for other video metrics. The context is strong but exclusions are absent.

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