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

Beyond the readOnlyHint and idempotentHint annotations, the description discloses key behavioral details: the polling cadence, the state machine (downloading -> pending -> transcoding -> ready), and the specific condition for meetsLaunchRequirements (4+ ready assets and 900+ seconds). These are non-obvious runtime behaviors that materially affect how the tool should be used.

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 description is dense but not bloated. It front-loads the core action, then proceeds through parameters, state details, and polling advice. Each sentence earns its place, though the sentence about meetsLaunchRequirements is somewhat long and could be split for readability.

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?

Given there is no output schema, the description does an excellent job of explaining what the caller will see: per-asset uploadStatus and the summary field meetsLaunchRequirements with its specific threshold. Combined with parameter semantics and polling guidance, the description leaves no critical gap for a status-checking tool.

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 input schema provides no descriptions for asset_id or channel_id (0% coverage). The description explicitly differentiates them: channel_id returns all videos for that channel, asset_id returns a single asset. This is exactly the kind of meaning the schema lacks, fully compensating for the schema's silence.

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 opens with the specific verb 'Poll' and the resource 'transcode progress', making the tool's function immediately clear. It further specifies the two input modes (channel_id vs. asset_id), which distinguishes it from sibling tools like retry_transcode or import_video_from_url.

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?

The description gives a clear usage context by explaining when to poll ('Poll every 30-60s') and the expected duration ('transcoding takes roughly real-time/4'). It does not explicitly mention alternatives or exclusion cases, but the purpose is unambiguous enough that an agent would know this is for status checks rather than actions like retry.

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