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

Annotations declare readOnlyHint=true and openWorldHint=true, and the description adds meaningful context beyond that: it reads the user's real connected channel, requires no input, and should be called immediately without asking questions. It does not detail rate limits or timeouts, but for a read-only review tool the remaining behavioral context is minor.

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 core purpose is front-loaded, but the description is long, includes many repeated trigger phrases and several admonitions ('never ask the creator anything first', 'call it immediately') that could be trimmed. It is informative but not concise.

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 zero-required-parameter, read-only tool with no output schema, the description covers what the tool does, when to use it, how to pick a video, and its relationship to siblings. It omits only a few behavioral details (e.g., latency, failure modes), which are minor for this tool type.

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 50%—the `video` parameter is documented in the schema, but the `title` parameter has no schema description. The description adds semantics for `video` (partial title, omit for most imminent) but says nothing about `title`, which is unexplained in both places. Baseline 3 is appropriate, with a small residual gap.

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 states a precise verb and resource—reviewing an upcoming (scheduled, unlisted, private/draft) YouTube upload and producing a prioritized fix list—and explicitly contrasts the target with analyze_video (already public) and package_video (titles/thumbnails alone). An agent can distinguish this tool from all siblings without opening a schema.

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?

It gives explicit when-to-use triggers ('is my next video ready', 'review my video for tomorrow'), when-not-to-use alternatives (already public → analyze_video; titles/thumbnails only → package_video), and even when never to ask questions first. Routing is fully specified.

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