Edit image

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

Annotations already declare the safety profile (destructiveHint=false, idempotentHint=false), so the bar is lower. The description adds genuinely useful behavior beyond those: the input file is never overwritten and width/height/aspect ratio are preserved by default. It stops short of describing the return payload or latency, but the added mutation-safety context is solid.

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 short sentences, front-loaded with purpose, then the default behavior, then the non-destructive guarantee. Every sentence carries information and nothing is padded.

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 7-parameter non-read-only tool with no output schema, the description covers purpose, preservation default, and the no-overwrite guarantee. It does not address seed/quality trade-offs or what the result contains, but those are handled by the input schema and include_preview documentation. Sufficient, with minor room to grow.

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. The description's prompt example and the dimension-preservation default merely mirror what the schema already documents, adding no syntax or semantics beyond it.

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 gives a specific verb and resource ('Edit an existing image') plus the interaction mode ('natural-language instruction') with a concrete example. This clearly separates it from siblings like generate_image (creation), inpaint_image/outpaint_image (region-specific operations), and edit_images (plural/batch).

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 is implied by 'Edit an existing image', and the default dimension-preservation behavior is stated, but the description never says when to prefer this over edit_images, inpaint_image, or outpaint_image, nor does it state prerequisites. No exclusions or routing guidance is offered.

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