youtube_video_info

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

Lists return fields and describes direct lookup behavior. No annotations provided, but description lacks details on error handling, rate limits, or authentication needs.

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?

Two concise sentences front-loaded with purpose, followed by return fields and behavior. No redundant words.

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?

Covers basic usage and return fields, but lacks error scenarios. Given the tool's simplicity and existence of output schema, completeness is adequate but not exhaustive.

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?

Adds value beyond the schema by clarifying the parameter accepts either a URL or an ID, which is not obvious from the schema alone.

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?

Clearly states it gets video metadata by URL or ID. Distinguishes from search tool by specifying 'direct lookup' and 'no search required'.

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?

Provides clear context: use when you have a specific video URL or ID. Implicitly contrasts with youtube_search, but doesn't mention other siblings like youtube_channel_info.

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