Youtube Channel Catalog

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

Annotations already cover the safety profile (readOnly, idempotent, openWorld), so the bar is lower, yet the description adds genuinely useful context: it clarifies that video counts and playlist totals are provider metadata and that no video bytes are fetched. This warns the agent that reported totals may not match returned items, which annotations do not convey.

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 action is front-loaded in the first sentence and the three sentences are largely free of padding. The phrasing 'The returned items establish this page's coverage' is slightly abstract, but nothing is wasted.

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?

An output schema exists, so return values need not be explained, and the description correctly focuses on scope (one page) and the metadata-only nature of the call. It is nearly complete; a note on how to obtain the next page token would close the remaining gap.

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 all three parameters (max_items, reference, page_token) are already documented in the schema. The description's mention of the continuation token loosely maps to page_token but adds no format or syntax detail beyond what the schema provides, so baseline 3 applies.

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 (List) and resource (one channel uploads page) and makes the single-page scope explicit, which is meaningful given the paginated nature. It does not, however, explicitly distinguish itself from siblings like youtube_channel_inspect or video_playlist, leaving the agent to infer the boundary.

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?

Mentions retaining a continuation token, which implies the one-page-at-a-time paging workflow, but never states when to choose this tool over youtube_channel_inspect, video_playlist, or video_metadata. Usage is implied rather than spelled out.

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