copy_region

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

With no annotations provided, the description fully bears the burden of behavioral disclosure. It clearly states three key behaviors: coordinates are sprite-global, transparent source pixels do not overwrite, and the destination cel is created when missing. This adds significant context beyond the schema.

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 well-structured with a one-line summary, followed by important behavioral notes and a parameter list. It is front-loaded and every sentence adds value. There is no wasted text.

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 tool with 11 parameters and no output schema, the description covers purpose, parameters, and key behaviors thoroughly. However, it does not mention return values (e.g., success/failure feedback) or error conditions. This is a minor gap given the tool's complexity.

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?

The input schema has 0% description coverage, so the description must explain each parameter. It does so comprehensively in the 'Args' section, providing clear semantics for all 11 parameters, including default behaviors for optional ones. This fully compensates for the schema gap.

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 copies a rectangular region of pixels to another position, layer, or frame. It uses a specific verb ('copy') and resource ('region'), and 'Coordinates are sprite-global' adds precision. This distinguishes it from siblings like 'move_region' or 'copy_cel'.

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 explains what the tool does but does not explicitly state when to use it versus alternatives. It mentions behaviors like 'transparent source pixels do not overwrite' but lacks guidance on when not to use (e.g., for moving instead of copying). No alternative tools are referenced.

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