Generate an image

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

It adds meaningful behavioral detail beyond the annotations by disclosing the credit-spending side effect and the 'prepares and verifies without sending' dry-run mode. This complements the destructiveHint/readOnlyHint annotations without contradicting them.

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 compact sentences front-load the core action and then cover credit spending, dry-run behavior, and resume behavior. Every sentence carries operational weight with no filler.

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 10-parameter open-world tool with destructive and cost implications, the description conveys the most important operational semantics and benefits from annotations and an output schema. Still, required-parameter meanings and prerequisites like an active Flow connection/project are left to inference, leaving clear gaps.

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 only 20%, and the description compensates mainly for auto_confirm and resume. It does not explain required parameters like prompt, project_url, and output_dir, nor does it add context for model, ratio, count, job_id, or reference_images beyond what their names/defaults imply.

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 opens with a specific action—generate and download images—and names the Flow agent composer (Nano Banana models) as the resource. It clearly separates image generation from the sibling video generation tool, though it does not explicitly distinguish itself from a download-only sibling like flow_media_download.

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 useful mode-based guidance: auto_confirm=false validates without spending credits, auto_confirm=true sends and spends, and resume=true only waits for/downloads an in-flight generation. However, it does not explicitly state when to prefer this tool over flow_media_download or what preconditions like an active Flow connection/project are needed.

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