recraft_replace_background

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

With no annotations, the description carries the full burden. It states the core behavioral effect ('Replace the background... Keeps the subject, changes the scene') and calls out a model restriction. However, it does not disclose whether the original file is modified or a new image is returned, the output format, or any side effects, which is a notable gap for an image-generation tool.

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?

Two concise sentences with no filler. The core function is front-loaded, and the additional semantic clarification ('Keeps the subject, changes the scene') earns its place. The model limitation is stated efficiently.

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?

Despite having 10 parameters, nested objects, no annotations, and no output schema, the description offers only a brief purpose statement and model note. It omits usage scenarios, sibling-tool differentiation, and return-value behavior, which an agent would need for this complex tool.

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 schema already documents all parameters. The description adds no extra meaning about parameters beyond implying that the prompt describes the new background, which is minimal but acceptable given the schema's completeness.

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 has a specific verb ('Replace'), a clear resource ('the background of an image'), and the key outcome ('Keeps the subject, changes the scene'). This distinguishes it from sibling tools like recraft_remove_background and recraft_generate_background without needing to open their schemas.

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 conveys when to use this tool: when the intent is to preserve the subject while generating a new scene. It also states an explicit model constraint ('V3/V3 Vector only'), which helps the agent avoid invalid calls, though it does not explicitly name alternative tools or provide when-not-to-use guidance.

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