fill_area

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does not mention that flood fill overwrites existing pixels, how tolerance affects behavior, or whether the operation is reversible. The description only states the basic mechanism without disclosing the destructive nature or edge-case behavior.

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 single, highly concise sentence that front-loads the core purpose. Every word earns its place, and the paint bucket analogy adds clarity without bloat.

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 the tool has six parameters, no output schema, and no annotations, the description is severely under-specified. It lacks any explanation of return values, coordinate systems, or how optional parameters like frame and layer affect the operation. More context is needed for an agent to use it 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 only 33%, and the description does not compensate. It refers to 'a point' but does not explicitly identify x and y as the starting coordinates, nor does it explain frame or layer parameters. Only color and tolerance have schema descriptions; the description adds no additional parameter meaning.

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 clearly states the tool's purpose with a specific verb ('flood fill') and resource ('an area starting from a point'), and the paint bucket analogy makes it immediately recognizable. It clearly distinguishes from sibling drawing tools like draw_pixels or draw_rect.

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 paint bucket analogy provides clear context for when to use the tool, but it does not explicitly mention alternatives or situations where another tool should be used instead. There is no when-not guidance, so the usage guidance remains implied rather than explicit.

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