9router video

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

Annotations provide no safety hints (all false), so the description must carry behavioral disclosure. It only vaguely notes 'Speculative on this host', which suggests reliability concerns but doesn't detail side effects, permissions, or output characteristics. This is insufficient for a generation tool.

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 extremely short, but brevity is achieved by omitting essential information rather than by efficient structuring. The sentence about being 'speculative' is tangential and doesn't earn its place given the lack of core usage details.

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?

Despite having an output schema, the tool is complex (video generation) with three parameters at 0% schema coverage. The description fails to explain what the tool does beyond the basic verb, leaving the agent without necessary context to use it correctly.

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 0%, and the description mentions none of the parameters (prompt, model, timeout_seconds). The agent gets no additional meaning beyond the bare property names, making it impossible to understand how to fill them correctly.

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 states 'Video generation' which clearly identifies the verb and resource, distinguishing it from siblings like nine_image or nine_tts. However, it lacks any elaboration on what the tool does beyond that, so it doesn't fully clarify scope or behavior.

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?

There is no guidance on when to use this tool versus alternatives. The phrase 'Speculative on this host; kept for others' hints at environmental limitations but doesn't explain when to invoke it or when to prefer another generation tool.

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