youtube_essence

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds no behavioral traits beyond these, such as external API dependency or rate limits. Despite annotations covering safety, the description misses contextual details like needing internet access.

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 very concise: a single sentence defining purpose followed by a well-structured Args list. Every sentence is meaningful, and the structure is front-loaded with the core action.

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 (2 parameters, no nested objects), the description covers purpose, parameters, and output types. It lacks information on error handling or return format, but the existence of an output schema mitigates this. Overall, it is adequately 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?

With 0% schema description coverage, the description fully compensates by explaining the 'url' parameter with allowed formats and the 'mode' parameter with three depth levels and their effects. This adds significant meaning beyond the raw schema.

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 the action ('Extract essence') and the resource ('YouTube video'), followed by a list of outputs (transcript, summary, key points, chapters, quotes). This distinguishes it from siblings like twitter_extract or fetch_url which target different sources or actions.

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 usage context via parameter explanations (allowed URL formats and mode options). However, it does not explicitly mention when to use this tool over alternatives or exclude scenarios, though the specificity to YouTube serves as implicit guidance.

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