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

Annotations already indicate readOnlyHint=false and destructiveHint=false. The description adds useful behavioral context: fixed duration (5 seconds), lack of audio, expected cost, and processing time. This enriches the agent's understanding of the tool's behavior beyond the schema and 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 a single, information-dense sentence containing the action, model, duration, audio status, cost, and processing time. Every word adds value with no redundancy.

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 generation tool with 2 parameters and an output schema, the description covers key operational facts (length, audio, cost, latency). The only omission is differentiation from sibling video tools, but the core usage context is well addressed.

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%, so the description does not need to explain parameters. The description mentions fixed output characteristics (5 seconds, no audio) but no additional meaning for 'prompt' or 'aspect_ratio' beyond the schema.

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 clearly states the tool generates a 5-second video using Kling 2.6 and specifies no audio. It distinguishes itself from sibling tools by naming the specific model, duration, and audio absence.

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 provides cost (~$0.60) and latency (1-3 minutes), which imply suitability for quick/cheap video generation, but it does not explicitly compare with alternatives like ai_video_seedance or ai_video. No exclusions or when-not-to-use guidance is given.

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