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

Annotations already cover the read-only safety profile, so the description adds genuine behavioral context: the MP4 link is kept only 30 days, and failed jobs refund credits. Those consequences cannot be derived from the annotations or the one-parameter schema.

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 compact sentence front-loads the tool's identity and then pairs each state with its consequence. There is no filler, and the state/result mapping is easy to scan.

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?

For a one-parameter polling tool with no output schema and annotation-covered safety, the description supplies what matters: the input source, state enumeration, output artifact, retention window, and failure compensation. Minor gaps remain around polling cadence and whether done/failed are terminal states.

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 id parameter is already documented as the value render_video returned, with a vid_ prefix example. The description reinforces the linkage to render_video but adds no format or syntax detail beyond the schema, so the 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?

States a specific verb and resource ('Status of a render_video job') and enumerates the possible states — queued, rendering, done, failed — so an agent can distinguish it from render_video itself and from sibling status tools like account_status.

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?

Implies usage by referencing the id that render_video returned, making clear this is the follow-up call after submitting a render job. It stops short of explicitly stating when not to use it or naming alternatives, so guidance is implied rather than spelled out.

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