youtube_list_videos

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 it's a read operation implicitly ('List videos... Returns video summaries with stats'), notes the uploads-playlist proxy mechanism, and indicates result ordering. However, it doesn't disclose whether auth is required for the 'mine' path, what happens when no IDs/mine are given (error vs default behavior), or pagination details beyond max_results max of 50. Since this is a mutation-free listing tool, disclosure is adequate but not rich.

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?

Well-structured with a summary line followed by a 'Args' list. Efficient and scannable. The Args section is brief but the sibling-tool context shows many alternatives, and the description correctly focuses on what this tool uniquely does. Slight redundancy in stating channel vs playlist modes, but overall lean.

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 listing tool with no output schema and no annotations, the description explains the core behavior (returns summaries with stats, most-recent first), the three access modes, and the max limit. This is reasonably complete for the tool's complexity. It could clarify default behavior when no source is specified and whether 'mine' requires prior auth, but given the tool's simplicity, this is near-complete.

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 fully, and it does. It explains channel_id (uses channel uploads playlist), playlist_id (overrides channel_id), mine (authenticated user's videos), and max_results (max 50). This adds meaningful context beyond the raw schema types, though it could note the relationship that mine and channel_id are mutually exclusive or that exactly one source must be chosen.

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 states the verb (List) + resource (videos from a channel or playlist) and distinguishes two usage modes (channel vs playlist). It differentiates from siblings: youtube_get_video is singular, youtube_search is by query, youtube_list_comments is comments. However, it doesn't explicitly name alternatives like youtube_get_video, though the purpose is 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 explains the channel vs playlist vs mine vs max_results modes and notes playlist_id overrides channel_id. It states 'sorted by most recent' which helps selection. However, it doesn't explicitly say when to use this vs youtube_search or youtube_get_video, nor mention that channel uploads playlist is used as a proxy. Implied usage, not explicit exclusions.

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