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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, yet the description adds genuinely useful behavior: the exact fields returned, the shorts array wrapper, nullability of publishDate, the need to re-request with continuationToken, and a cost signal. The cost information is muddled — "at least 10 Nexscope credits" versus "1 credit per request" — which undercuts an otherwise strong disclosure.

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 publishDate nullability rule is stated twice in near-identical wording, and the text is padded with pasted supplier boilerplate ("YouTube Channel Shorts API View Pricing Get channel Shorts", "Actual supplier units are reported per request. Examples are not guaranteed prices.") plus two conflicting credit figures. The substantive content would fit in three sentences.

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?

With no output schema, the description does the necessary work of naming the returned fields and the shorts array, and it explains pagination and cost. But it omits the single most important calling precondition — which of handle/channelId to pass when the schema marks none as required — and the cost contradiction leaves billing ambiguous.

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 100%, so the schema already documents sort, handle, channelId, and continuationToken; baseline is 3. The description adds essentially nothing beyond that, and notably fails to resolve the ambiguity the schema leaves: zero parameters are required, yet at least one of handle/channelId must logically be supplied to identify a channel, and the description never says so.

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 opens with a specific verb+resource+scope: "Retrieves a paginated list of short-form videos (Shorts) from a YouTube channel," and enumerates the returned fields. It implicitly distinguishes itself from social_youtube_channel_videos (short-form only) but never names that sibling or social_youtube_shorts_trending, so the differentiation is left to inference.

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?

It gives real usage mechanics — "Supports sorting by newest or popular; use the continuationToken to page through all results" — which tells the agent how to paginate. However, it never states when to choose this over the very similar siblings (channel_videos, shorts_trending), nor any precondition such as needing a channel identifier.

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