Generate a video

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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), and the description adds real behavioral context beyond that: it consumes one video generation from the plan allowance, counts toward a daily video quota, returns immediately with a job id, and takes one to several minutes. Failure modes and quota-exhaustion behavior are not described, keeping it short of a 5.

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?

Three sentences, zero filler, and the most decision-relevant information (what is generated and from what inputs) is front-loaded, with the quota/async caveats following.

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?

Complete for an async job-launching tool with no output schema: the description explains that the immediate return is a job id, that completion is non-instant, and which sibling tool reports progress. Nothing needed to invoke it correctly is missing.

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 every parameter is already documented in the schema (including the image-to-video semantics of the source_* fields and the 1080p cost caveat). The description's contribution is mostly a restatement of the three source modes rather than new syntax or format guidance, so the baseline 3 applies.

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+resource ('Start an ad video generation') and immediately enumerates both modalities (text-to-video, image-to-video from source_image_path/source_image_url/source_job_id). This clearly separates it from the sibling adsoptimiser_generate_image and adsoptimiser_batch_generate without requiring a schema read.

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?

Gives clear context for when each mode applies (text-to-video vs. image-to-video conditioned on which source parameter is supplied) and explicitly routes progress checking to adsoptimiser_get_job. It stops short of stating exclusions, e.g. when to prefer adsoptimiser_generate_image or adsoptimiser_batch_generate for multi-video workloads.

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