Vertex.Veo.Generate

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

With no annotations, the description carries the full burden; it usefully discloses two traits an agent could not infer: the call is asynchronous (returns an operation) and it is billed. It stops short of stating permission/auth needs, latency expectations, or constraints on duration/model, which matter for a paid 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?

Two compact sentences, front-loaded with the verb and resource, followed by the operational and cost caveats. No padding.

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?

An output schema exists, so return-value explanation is not required, and the async-plus-poll contract is covered. But with 0% parameter coverage and no annotations, the description leaves model options, duration limits, and usage boundaries undocumented for a costly generation tool.

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% across three parameters, so the description must compensate and does not: it says nothing about the meaning or valid values of model, prompt, or duration_seconds. Only the tool-level subject (video generation) implies what prompt is.

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 a specific verb and resource ("Generate a video clip with Veo 3.1") and identifies the Veo model version. It routes the agent to vertex.veo.status for polling, but does not distinguish itself from the sibling video.generate, which is potentially confusable.

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 phrase "returns an operation to poll with vertex.veo.status" gives a clear follow-up workflow, and "Incurs Vertex cost" flags a decision factor. However, there is no guidance on when to pick this versus video.generate or vertex.imagen.generate, and no stated exclusions or prerequisites.

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