erase_region

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

The description discloses the effect (makes transparent) and coordinate system, but does not mention edge cases, undo behavior, or potential side effects. Without annotations, this is adequate but not thorough.

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 concise: a one-line summary, a coordinate note, and a clean list of parameters. No unnecessary information, well-structured.

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 simple tool with 7 required params and no output schema, the description covers the functionality and parameter semantics well. Minor gap: no mention of handling dimensions exceeding canvas bounds.

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?

Although schema coverage is 0%, the description provides a dedicated 'Args:' section explaining each parameter (filename, layer_name, frame_index, x, y, width, height), adding meaning beyond the schema.

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 erases (makes transparent) a rectangular region of pixels, specifying coordinates are sprite-global. This distinguishes it from sibling tools like clear_cel or draw_rectangle.

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 implies usage when erasing a rectangular region, but it does not explicitly state when to use this tool over alternatives (e.g., clear_cel for full cel erasure) or any prerequisites.

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