List channel videos

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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so safety is covered. The description adds genuinely non-obvious behavior: the median is computed only over the videos returned, so the limit matters for score fairness, and dates may be approximate. It does not discuss pagination or rate limits, but for a read-only listing that is a minor gap.

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?

Three short blocks — what it does, when to use it, what it returns — with the outlier definition front-loaded. Every sentence carries information; nothing is restated from the schema verbatim.

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?

There is no output schema, and the description compensates by summarizing the return payload (channel stats plus per-video views, outlier multiple, date, duration). Combined with the six documented parameters and the median caveat, an agent has everything needed to call it 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 coverage is 100%, so the baseline is 3, but the description adds meaning beyond the schema: the 30+ recommendation for a stable median ties the `limit` parameter to result quality, and the minOutlier caveat is restated in context. This helps an agent choose values rather than just syntax.

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 and resource ('List a channel's videos') and immediately adds the differentiating feature — the outlier score defined inline as views relative to the channel median. This clearly separates it from youtube_search (query-based) and youtube_fetch (single-video retrieval) without opening a 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?

The 'Best for:' line enumerates three concrete jobs (finding breakout videos, reviewing recent uploads, building a list to fetch), the last of which implicitly routes to youtube_fetch. It stops short of an explicit exclusion rule naming the alternative tool and its trigger condition, so it is clear context rather than full routing guidance.

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