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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external-network behavior are covered. The description usefully adds the per-call cost (40 points) and the fact that both profile and recent video data are returned, but it omits how many videos, whether results are paginated, or any rate limits.

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?

Two short bilingual sentences plus a bracketed cost note, with the core purpose front-loaded in the first sentence. Every sentence carries content, though the full Korean restatement is somewhat redundant with the English.

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 should explain the return shape, and it does name the two data sets (profile + recent videos). However it leaves the volume/format of returned videos unspecified, and gives no guidance for choosing it over sibling youtube tools.

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% and the single parameter's schema description already enumerates the accepted forms (channel ID, handle, channel ID UC…, or URL). The description adds nothing beyond the schema, so the 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 (collect) and resource (YouTube channel profile + latest uploaded videos), naming both artifacts returned. It does not, however, differentiate itself from siblings like youtube_channel or youtube_metadata, which the agent would have to disambiguate on its own.

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?

There is no when-to-use guidance and no mention of alternatives among the many youtube_* siblings (youtube_channel, youtube_metadata, youtube_search). The only usage signal is the point cost, which is a pricing hint rather than a selection rule.

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