generate_video

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

With no annotations, the description carries the full burden. It discloses that generation takes 1-3 minutes, returns an operationId immediately, and lists limitations like 'Audio file references are not supported'. It is transparent about async behavior but could mention authentication requirements or rate limits.

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, well-structured paragraph. It front-loads the essential action ('Returns an operationId immediately') and then provides detailed options and constraints without redundancy. Every sentence adds value.

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 17 parameters and no output schema, the description covers the necessary context: modes, polling workflow, unsupported features, file types, and combination rules. It equips the agent to select and invoke the tool appropriately.

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 baseline is 3. The description adds significant value by summarizing common usage patterns (text-to-video, image-to-video, interpolation) and providing constraints (e.g., 'videoPath must be MP4 from a previous Veo 720p generation'). This helps the agent understand parameter relationships 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 it starts video generation using Google's Veo models, specifying multiple modes (text-to-video, image-to-video, etc.). It distinguishes itself from sibling tools like generate_image and check_video by focusing on video generation and referencing the polling workflow.

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 instructions: 'Use check_video with the operationId to poll for completion' and recommends a 30-second polling interval. It also clarifies what is not supported (audio file references). However, it does not explicitly state when to avoid this tool in favor of alternatives.

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