Check a video's render status

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds substantial behavioral context beyond that: it explains the meaning of each status, that 'done' provides output_url and share_url, that 'failed' triggers an automatic credit refund, and that a render typically takes a few minutes. It also warns against tight polling, which is a behavioral trait an agent needs. No contradiction with annotations.

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 moderately long but every sentence earns its place. It front-loads the purpose, then uses a bulleted list to enumerate statuses and actions. It could arguably be tightened by trimming the 'pending' line, but overall it's well-structured and free of fluff.

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 status-check tool with a single parameter and no output schema, the description is fully complete. It covers all possible status values, the meaning of each, the appropriate agent action for each, and the expected duration. It also tells the agent how to behave (inform the user). Nothing an agent needs to call the tool correctly is missing.

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% — the single parameter video_request_id already has a clear description ('Returned by generate_video, and listed under videos in get_product'). The tool description does not add any additional parameter-level semantics, and with full coverage the baseline of 3 is appropriate.

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 'Check one video's render,' which is a specific verb (check), a specific resource (one video), and an action (render status). It clearly distinguishes itself from generate_video (which creates) and get_product (which lists videos), so an agent can tell them apart without reading the schema.

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 explicit when-to-use guidance: each status value comes with a recommended action — poll every 20-30 seconds for 'generating', call generate_video for 'pending', etc. It also tells the agent to inform the user rather than poll silently, which is a clear usage directive. There are no explicit exclusions, but the status-based routing fully covers the decision space.

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