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

The description clearly discloses the asynchronous behavior and the need to poll get_generation, which is not evident from annotations. It also mentions cost ('from $0.60'), adding transparency beyond the openWorldHint and readOnlyHint false annotations. 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?

Two concise sentences with no wasted words. The core action is front-loaded, followed by cost and the essential async polling instruction. Every part earns its place.

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 tool with 3 parameters, full schema coverage, and an async pattern, the description covers the key operational steps: it states the purpose, the async nature, how to retrieve the result, and cost. It doesn't cover error handling or edge cases, but these are not essential for basic invocation.

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%, so the schema already fully documents video, prompt, and quality. The description adds no additional parameter details beyond what's in the schema, so it meets the baseline of 3 but does not exceed it.

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 the specific action 'Restyle videos with a prompt', which is clear and distinct from other video tools like colorize, upscale, or extend. The verb 'restyle' is specific enough to separate it from siblings, though it doesn't explicitly name alternatives.

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?

Provides usage context for the asynchronous flow (returns generation_id, poll get_generation) but gives no guidance on when to choose this tool versus other video-restyle or editing tools. The polling instruction is useful, but there's no explicit when/when-not guidance.

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