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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's real contribution is the result shape: which status values appear and that a signed download URL is only present once done. That is meaningful behavior beyond the annotations, though polling cadence and URL expiry are left unstated.

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 compact sentences, front-loaded with the action and result states, with no redundant phrasing. Every clause carries 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?

An output schema exists, so return values need not be fully described, and the description still summarizes the important states and the conditional download URL. A note on whether to poll repeatedly or how long the signed URL lasts would close the remaining gap.

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 coverage is 100% and the single render_id parameter is already documented as a uuid from grok_generate_video. The description repeats that provenance rather than adding new detail, so the schema does the heavy lifting.

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 ('Check') and resource ('a video render's progress') and enumerates the outcome states (queued/rendering/done/failed) plus error detail and download URL. This clearly separates it from grok_generate_video, the sibling that creates the render.

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?

Says where ids come from ('Ids come from grok_generate_video'), which tells the agent the intended call sequence: generate, then check status. It does not spell out when not to use it or whether repeated polling is expected, but the context is unambiguous.

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