prepare_concept

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

With no annotations provided, the description carries the burden of disclosing behavior. It does so effectively by stating refusal conditions ('Refuses inputs whose corners disagree (busy background)') and warning behavior ('Warns when the opaque fraction looks like a bad key'). These are meaningful beyond what the schema reveals.

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 three sentences, front-loaded with the core action, and every sentence adds unique value: the operation, the relationship to generate_model, and two behavioral constraints. No wasted words.

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?

The description covers purpose, usage context, behavioral edge cases, and output format. An output schema exists, so return details are not needed. The only gap is the lack of parameter-level explanation, but overall the description is sufficiently complete for a moderately 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 0%, so the description must compensate by explaining the parameters. It mentions the concept image as input and RGBA PNG as output, but it never maps these to the actual parameter names (image_path, output_path) or clarifies output_path's null default behavior. The parameter semantics are under-specified.

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 verb-resource statement: 'Key a plain-background concept image out to a centered square RGBA PNG.' It also explicitly distinguishes itself from a sibling tool ('Standalone version of generate_model's auto_cutout'), making its unique role clear.

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 names the alternative (generate_model) and specifies the intended use case ('for callers that want the intermediate'). It implies when this tool should be chosen over the sibling but does not explicitly say when NOT to use it in favor of other alternatives, so it stops short of full guidance.

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