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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is fully covered. The description adds context beyond that: the useful disclosure that the returned download_url is temporary and only present when status is "done", which tells the agent to consume it promptly.

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?

Two short sentences with zero waste; the core check action is front-loaded and the important result caveat follows immediately. Nothing could be removed without losing information.

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 explaining return values, yet it only documents the "done" case. It says nothing about other possible status values, what the result looks like while still running, or what happens if wait_seconds elapses before completion – all material for a polling 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?

Schema description coverage is 100% and both parameters (job_id sourced from download_video, wait_seconds with default 20 and 0-120 bounds) are documented in the schema itself. The description adds no parameter-level detail beyond the schema, so baseline 3 applies.

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?

"Check a download" gives a specific verb and resource, and the mention of a terminal "done" status plus download_url makes the polling purpose unambiguous. Sibling differentiation is only implicit (job_id ties it to download_video), but the name and description together leave no doubt about which tool handles status vs. cancel or fetch.

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 implies a poll-after-download workflow but never states when to call it or how it relates to download_video and cancel_download. There is no explicit guidance on when not to use it or how to sequence it against the siblings, leaving the agent to infer the usage pattern.

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