list_captions

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

Annotations already declare this as a safe read (readOnlyHint=true, destructiveHint=false). The description adds genuine behavioral context beyond them: no audio download and no Whisper execution, telling the agent this is a cheap metadata-only call rather than an expensive processing job. It stops short of stating whether results are cached or how large the listing can be.

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?

One sentence, front-loaded with the action and resource, with the clarifying cost caveat trailing. No wasted words.

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 unnecessary, and the read-only annotations cover the safety profile. The only real gap is the undocumented 'video' argument format, which leaves a small hole for a required parameter.

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 single 'video' parameter has 0% schema description coverage, and the description says nothing about what form it takes (ID, URL, path) or any constraints. With coverage this low, the description was expected to compensate and 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 gives a specific verb and resource ('List available caption languages/types') and implicitly separates itself from get_transcript by noting it does not download audio or run Whisper. It does not name the sibling tools directly, but the scope is unambiguous.

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 implied: check what caption tracks exist before committing to a heavier transcription path. There is no explicit when-to-use/when-not statement and no direct routing to get_transcript or get_status, so an agent must infer the workflow.

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