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

Annotations already mark it read-only, and the description adds useful behavioral details: it reports pending/done/failed statuses and explicitly states failed attempts are not charged. The word 'Free' further clarifies the cost behavior beyond the annotation hints.

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 conveys the purpose, the possible outcomes, and the cost guarantee. No filler or redundant wording, with the essential action front-loaded.

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 simple status-polling tool with two well-documented parameters and read-only annotations, the description is sufficient. It explains the statuses and the failure/cost behavior, and the schema covers the rest; no output schema is expected given the simple return concept.

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?

The schema already describes both parameters thoroughly, including that id comes from generate_video and that quote returns the price without executing. The description adds no extra parameter-level meaning, so 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 uses a specific verb ('Read') and resource ('status of a video you started') and enumerates the possible outcomes: pending, done with URL, failed and not charged. This clearly distinguishes it from generate_video, which creates the video, and from other unrelated siblings.

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?

It clearly implies the tool is used after starting a video generation, and the schema reinforces that the id comes from generate_video. However, it does not explicitly state when not to use it or mention any alternatives.

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