youtube_get_video_details

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

No annotations are provided, so the description carries the full burden. It discloses the return fields (title, description, tags, etc.) and batching efficiency (50 per API call), which adds value. However, it omits details like rate limits, authentication requirements, or error handling, which could impact invocation. This is adequate but not rich.

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, front-loaded with the core purpose, followed by a concise list of return fields and batching behavior. Every word earns its place, with no redundancy or filler.

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?

For a simple single-parameter tool with no output schema, the description provides a comprehensive list of return fields and batching behavior, giving the agent a clear picture of what to expect. Minor gaps exist, such as definitions of 'engagement rate' and 'view velocity' or error scenarios, but for a read-only metadata fetch, the description is largely 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 a single parameter 'videoIds' clearly described as an array of YouTube video IDs (max 50). The description's mention of 'Batches efficiently (50 per API call)' reiterates the schema's max constraint, adding marginal semantic value. Baseline 3 is appropriate given high schema coverage.

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 'Fetch full metadata and calculated engagement metrics for one or more video IDs' – a specific verb and resource. This distinguishes it from sibling tools like youtube_search_niche, youtube_get_channel_details, and youtube_get_thumbnails by focusing on video ID-based metadata retrieval.

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 implies usage when you have video IDs and want metadata, but it does not explicitly mention when to avoid this tool or name alternatives. The presence of sibling tools like youtube_get_channel_details and youtube_search_niche suggests different use cases, but the description does not reference them, leaving the agent to infer boundaries.

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