get_fill_image

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

With no annotations provided, the description carries the full burden. It discloses the return format (base64 JPEG), resizing behavior, inclusion of original URL in metadata, and all error/message outcomes. This is exceptionally transparent for a tool with no structured annotation context.

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 compact paragraph with no redundancy. It front-loads the core action, then efficiently covers resizing, the URL fallback, and all error cases. Every sentence earns its place.

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?

Given there is no output schema, the description covers the return format (base64 JPEG), handling of large images, the original URL, and all failure modes (missing node, no image fill, SVG, still generating). It references the relevant sibling for SVG and the polling mechanism for pending images. Nothing essential is missing for an agent to call this correctly.

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% – both fileId and nodeId have explicit descriptions. The tool description adds no additional parameter-level meaning beyond the schema. Since the schema already documents semantics, the baseline of 3 is appropriate.

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 states a specific verb ('Extract'), a resource ('image data from a node that has an image fill'), and clearly distinguishes itself from siblings by explicitly naming get_jsx for SVG cases. Its purpose is unambiguous and immediately actionable.

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 provides clear conditions for use: it works on nodes with image fills, and explicitly routes SVG cases to get_jsx. It also advises polling get_node_info when images are still generating. It lacks broader exclusions (e.g., when to use get_screenshot or export instead), but the primary alternative is addressed.

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