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

Annotations already declare read-only and open-world behavior, so the description carries a lower burden. It adds useful behavioral context by noting that the data is public, includes view/like counts, and costs 1 credit, but it does not explain cache behavior or limitations around private/deleted videos.

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 short, front-loaded, and wastes little space. The phrase 'video or Short' is repeated, which is a minor redundancy but not harmful.

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 detail endpoint with annotations and no output schema, the description covers the core return content and cost. However, it leaves the cache_max_age parameter unexplained and does not address edge cases such as unavailable or private videos.

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 only 50%: the url parameter is documented in the schema, but cache_max_age has no description in either the schema or the tool description. The description adds no parameter meaning beyond what the schema already provides.

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 identifies the resource as a YouTube video or Short and specifies that it returns public metadata including view/like counts. It is specific enough to distinguish this from channel-level or search tools, though it does not explicitly contrast with related endpoints like youtube_videoComments or youtube_transcript.

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?

Usage is implied by 'Public metadata for a YouTube video or Short' and the cost note, but there is no explicit guidance on when to use this versus alternatives such as youtube_videoComments, youtube_videoSponsors, or youtube_transcript. The agent must infer the intended scope.

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