YouTube: Get Channel

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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses that the result is scoped to the signed-in token's identity, that the call costs 1 quota unit, and the important failure-mode detail that a long-upload rejection only surfaces after the whole file is sent. It also points to the remediation path (phone verification URL). This is exactly the kind of behavioral context annotations cannot carry.

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?

It is front-loaded with the returned fields, then moves to the actionable warning and cost, with no filler sentences. The middle clause about `disallowed` or `eligible` is slightly dense and takes a second read to parse, which keeps it from a 5.

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 carries the burden of describing return values and does so by enumerating the fields. For a zero-parameter read tool this is nearly sufficient; it does not say what happens when no channel is authorized or the token is expired, which would require pointing at youtube_auth_status.

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?

The tool takes zero parameters, so there is no parameter semantics to explain; the schema baseline of 4 applies. The description's field list is about return values, not inputs, and the empty object schema is consistent with the account-scoped nature described.

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 resource (the channel the signed-in token acts as) and enumerates exactly what it returns: id, handle, uploads playlist, subscriber/video/view counts, and the `long_uploads` capability flag. That is far more concrete than the title alone. It does not explicitly contrast itself with siblings such as youtube_auth_status, which also concerns the signed-in identity, so it stops short of a 5.

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 states a clear usage condition: check `long_uploads` before attempting a long upload, because unverified channels (`disallowed` or `eligible`) fail only after the entire file has been transmitted. That is actionable when-to-use guidance rather than a restatement of the name. It does not name an alternative tool or say when not to call it, keeping it below a 5.

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