parse_youtube_url

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

The description details supported URL formats and extracted components, providing good transparency. No annotations exist, so description carries full burden. Does not mention error handling or return format, but sufficient for safe operation.

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 sentences, no fluff, efficiently conveys all necessary information. Well-structured and 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 only one parameter and no output schema, the description is complete. Agent can fully understand tool scope and invocation criteria. No missing details for effective usage.

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 already describes parameter as 'Any YouTube URL or video ID' (100% coverage). The description adds significant value by listing specific formats and extracted fields, enhancing agent understanding beyond 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 tool's purpose with a specific verb 'Parse' and specifies extracted elements (video ID, channel ID, playlist ID, handle, timestamp). It distinguishes from sibling tools which focus on data retrieval rather than URL parsing.

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 implicitly indicates usage for parsing YouTube URLs, but lacks explicit guidance on when to use or avoid this tool relative to siblings. No when-not or alternatives mentioned.

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