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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered; the description adds genuinely new behavioral context by listing the full status set and explaining that render_url is present only until the file exists while video_url appears once the MP4 is ready. The 'Free' note also discloses that calls consume no credit, which matters for a polling tool. Minor gaps remain (no rate limits, no behavior on an invalid or expired video_id).

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 dense sentence, front-loaded with the return contract and status values, ending with the cost note. Every clause conveys information an agent needs; nothing is padding.

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?

There is no output schema, so the description carries the burden of describing return values, and it does so well by naming the statuses and both URL fields with their conditions. It falls slightly short on edge behavior — what a failed status implies, whether statuses are terminal, and what an unknown video_id returns.

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 the single video_id parameter is already documented in the schema, including its provenance. The description adds only the implicit ownership constraint ('one of the user's videos'), which is useful but marginal; baseline 3 is appropriate when the schema carries the parameter documentation.

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?

States a specific verb and resource ('Returns where one of the user's videos stands') and enumerates the exact status values plus the URL fields returned. An agent can immediately tell this is a single-video status check, distinct from the sibling list_my_videos (bulk listing) and make_video (creation).

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 only implied: the schema note that video_id comes 'from make_video or list_my_videos' suggests this is the polling step after creation, and 'Free' signals it is cheap to call repeatedly. However, the description never explicitly says when to use this versus list_my_videos or quote_video, and gives no guidance on polling cadence or terminal states.

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