Youtube Get Video

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

With no annotations, the description carries the full burden and does so: it discloses quota cost (one unit per 50 IDs from a shared 10,000-unit daily pool), that a separate tool uses a different bucket, that parts increase response size but not quota, and that dislike counts are permanently unavailable. These are exactly the behavioral facts an agent cannot infer from the schema.

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?

Front-loaded with purpose, then usage, then parameter guidance, and each sentence carries unique information (quota, missing IDs, part semantics, dislike caveat). It is slightly long at three paragraphs, but nothing is padding.

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?

An output schema exists so return-shape detail is not required, yet the description still explains the one non-obvious return behavior (missing_video_ids). Combined with quota, batching, and part semantics, an agent has everything needed to call this correctly and interpret results.

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 description coverage is 0%, so the description must compensate, and it does: it explains that video_ids accepts a single string or an array of up to 50, and that parts selects snippet/statistics/contentDetails/status with a gloss for each enum value. This adds meaning well beyond the bare schema types.

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?

States a specific verb+resource ('Get YouTube video metadata by ID') and enumerates the returned fields (title, description, channel, duration, statistics). It also explicitly separates itself from the sibling youtube_get_video_stats, so an agent can route correctly without opening either schema.

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?

Gives explicit when-to-use-elsewhere guidance ('If you only need view/like/comment counts, use youtube_get_video_stats instead') and explains how to interpret the missing_video_ids result rather than treating it as a failure. It also states the batch limit (one ID or up to 50) that governs how to call it.

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