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

Annotations already cover the safety profile (readOnly, idempotent, closed-world, non-destructive), so the description's added value is the negative disclosure that it never returns a transcript or filesystem path — a genuinely useful boundary that prevents misuse. It omits what happens when the ID has no validated summary, which would be the one remaining behavioral 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?

Two short sentences with zero filler; the return-scope statement comes first and the negative boundary second. Nothing could be removed without losing information.

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-value explanation is not required, and the description still adds a useful boundary note. For a one-parameter idempotent read, the missing piece is only failure behavior for an unknown or unsummarized ID.

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 0%, so the description carries the burden for video_id. It tells the agent the value is a "known source ID" and that exactly one is expected, but gives no format, no example, and no hint about where to obtain a valid ID.

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 (return) and a precisely scoped resource: the validated eight-section Korean summary for a single source ID. The contrast with transcripts implicitly separates it from get_video, though no sibling is named explicitly.

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?

"for one known source ID" implies the prerequisite that the caller must already have an ID (presumably obtained via get_video), but this is left to inference. No explicit statement of when to prefer this over get_video or search_insights, and no guidance on what to do if no summary exists.

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