Generate image

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

Annotations already declare non-readOnly, non-idempotent, non-destructive, closed-world, so the safety profile is covered and the description builds on it usefully. It adds genuinely non-schema behavior: runs fully offline, typical runtime of 45 s to 4 min, and returns the absolute path of the saved PNG. It could have noted whether the model must be loaded or whether generation can be cancelled/queued.

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?

Four short sentences, each load-bearing: purpose, dimension defaults, return value, environment/latency. The core action and model are front-loaded, and nothing is restated from the schema.

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 no-output-schema generation tool the description covers the essentials an agent needs: what it produces, where the artifact lands, how long it takes, and that dimensions resolve automatically. Minor gap: it does not mention that the local model may need to be ready or how failures surface, despite a get_generator_status sibling.

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 the baseline is 3, but the description adds inference behavior the schema does not: aspect ratio can be parsed from the prompt text (e.g. '16:9 hero image') and dimensions default automatically. That is real added meaning beyond the per-parameter descriptions.

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 an image from a text prompt') and names the backing model (local Qwen-Image 2.1), which differentiates it functionally from the edit/inpaint/upscale siblings that take reference images. It never explicitly contrasts itself with those siblings, so an agent must infer the text-to-image vs image-editing split from the verb alone.

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?

Usage guidance is parameter-centric rather than routing-centric: it explains that dimensions are auto-chosen unless width/height or aspect_ratio are given, which tells the agent how to call it but not when to prefer edit_image, outpaint_image, or upscale_image instead. No prerequisites (e.g., model availability) are stated, though get_generator_status exists as a sibling.

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