fill_area

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

No annotations are provided, so the description must fully disclose behavior. It merely states it uses a paint bucket tool with coordinates and color, but omits details like whether the fill is destructive, applies to all layers, or how boundaries are determined (e.g., alpha threshold). The default color of black is noted but not the effect.

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 extremely concise: one sentence stating the tool's purpose, followed by a compact parameter listing in a consistent format. No unnecessary words or repetition. Front-loaded with the key action.

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 0% schema coverage, no output schema, and no annotations, the description is incomplete. It explains parameters but fails to describe return values, error conditions, or side effects (e.g., whether the file is modified in place). A paint bucket tool typically has flood-fill semantics that are not documented. Compared to the tool's complexity, more context is needed.

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. It provides explanations for all 4 parameters: filename as 'Name of the Aseprite file to modify', x and y as coordinates to fill from, and color as a hex code with default. This adds meaning beyond the schema's type and title fields, though more detail on coordinate system (e.g., layer vs canvas) would improve.

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 'fills an area with color using the paint bucket tool', specifying the verb (fill), resource (area), and method (paint bucket). This distinguishes it from sibling tools like fill_area_at which likely use a different approach.

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 no guidance on when to use this tool versus alternatives. It does not mention prerequisites, limitations, or when not to use it. Sibling tools exist for similar operations but no comparison is made.

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