summarize_video

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

With no annotations, the description itself discloses the JSON output structure, the dependency on captions (including auto-generated), and transcript sampling via coverage{}. It stops short of explaining failure modes when captions are unavailable, so not a full 5.

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?

Four sentences, each purpose-driven: statement of function, output shape, prerequisite, and when to use an alternative. No redundancy.

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?

The description covers function, output, prerequisite, and sibling differentiation. For a tool without an output schema, the return-field list adds necessary context, making it self-sufficient.

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% with meaningful parameter descriptions, so the description doesn't need to add param details. It does tie the tool's operation to captions, which is broader context rather than per-param semantics.

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 opens with a specific verb-resource pairing ('Summarize one YouTube video') and explicitly distinguishes itself from youtube_query for multi-video synthesis. Listing the return fields further clarifies the tool's scope.

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?

It explicitly states a prerequisite (captions required) and an alternative use case (multi-video synthesis → youtube_query with goal=advice), giving agents clear decision criteria.

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