Video analytics

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds two genuinely new behavioral facts: the data is 'private' (implying the caller must be authorized for that channel) and that impressions/CTR are only 'if available', warning the agent that some fields may be absent. It says nothing about latency, quota cost, or data freshness, so it earns a solid but not exceptional score.

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?

A single front-loaded sentence that opens with scope ('one video') before listing contents. Every clause names a distinct metric family, so nothing is filler, though the enumeration is dense and would read better split from the availability caveat.

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 the length spent enumerating return values is partly redundant with structured data. The description does cover the authorization-relevant 'private' nature, but with a three-parameter, open-world, authenticated tool it leaves out what happens on missing metrics beyond a parenthetical and any note on how days interacts with retention/CTR data.

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 100% — video_id, channel_id and the days window (with lifetime default) are all documented in the schema itself. The description adds no syntax or format detail beyond that, so the baseline 3 applies; the 'if available' caveat relates to output, not to parameter usage.

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 names a specific verb (retrieve analytics) and a precise scope ('for one video'), then enumerates the metric families returned (totals, impressions/CTR, traffic sources, retention, search terms). This clearly separates it from channel-level analytics, though it never names youtube_get_channel_analytics or youtube_compare_videos as the alternative scopes.

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?

Usage is only implied by the phrase 'for one video' — an agent can infer this is the per-video counterpart to channel-level analytics, but there is no explicit statement of when to choose this tool over youtube_get_channel_analytics or youtube_compare_videos, and no prerequisite guidance.

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