youtube_trending

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 quota cost (1 unit), which is a meaningful behavioral trait. It's a read-only operation implied by 'get', which is fairly clear. It could add more about what the response looks like, but the quota disclosure and the nature of the operation provide reasonable transparency for a read-only fetch tool.

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 compact and well-structured. The one-line purpose statement, quota note, and parameter list with clear formats/examples are front-loaded and efficient. No wasted words. It could format the args more tightly, but it earns its place with useful specifics like the ISO reference, the category example, and the max limit.

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 read-only fetch tool with 3 self-documented parameters and no output schema, this is reasonably complete. The quota disclosure compensates for missing annotations. It lacks detail about the response shape (fields returned per video) and pagination, which would push toward a 5, but for a straightforward trending list tool the description covers the essentials.

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. It provides inline explanations for all three parameters: region_code (ISO code with examples), category_id (with example '28' for Science & Technology), and max_results (with max 50 limit). This adds value beyond the raw schema, which only shows titles and defaults. However, coverage of each parameter's meaning is somewhat thin, and the category example is single.

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?

Description clearly states the purpose: 'Get currently trending videos on YouTube.' This is a specific verb+resource combination that distinguishes it from siblings like youtube_search (search by query) and youtube_list_videos (list channel/user videos). It doesn't explicitly name an alternative, which would be needed for a 5, but the contrast with trending vs. search vs. list is reasonably clear.

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 context (trending videos for a region/category) but doesn't explicitly state when to choose this over alternatives. It mentions the quota cost (1 unit) which is useful context. However, there are no explicit when-not-to-use conditions or named alternative tools, so it stops short of full guidance.

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