List caption tracks

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and access profile are covered. Beyond that, the description adds only a parenthetical list of fields, with no note on ordering, whether draft/auto-generated tracks are always included, pagination, or error behavior when the video is not owned by the caller.

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 a single short fragment with no wasted words, but the terseness crosses into under-specification: no verb, no sentence structure, and the parenthetical field list carries all the informational load. Short is good here, but it is not front-loaded around an actionable statement.

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 read-only listing tool with no output schema and no documentation of the required video_id, the description says nothing about return shape, ordering, or counts. An agent knows roughly what the tool returns but nothing about how to scope the call or what to expect back.

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 50%: the channel parameter is documented, but the required video_id has no description at all, and the description never mentions either parameter or how channel selection interacts with the default channel. With low coverage the description should compensate, and it does not.

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 is a bare noun phrase ('Caption tracks on a video') that names the resource and lists the fields returned but never states the verb; the agent must infer 'list' from the tool name and title. It also does not distinguish this tool from siblings such as download_captions, delete_captions, or upload_captions.

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 guidance on when to use this tool versus the four other caption-related siblings, no stated prerequisites (e.g. the video must exist and be accessible on the given channel), and no exclusions. The agent is left to infer that this is the read-only inventory call.

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