move_region

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

With no annotations, the description carries full behavioral burden. It discloses that source becomes transparent, pixels outside canvas are discarded, and transparent source does not overwrite destination. Missing details on undo or error handling.

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?

Well-structured: one-sentence summary, bullet-point behaviors, then parameter list. Every sentence adds value, no fluff. Front-loaded with key information.

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 9-parameter tool with no output schema or annotations, the description covers core behavior well (source/destination, transparency handling). Could mention undo capability or partial out-of-canvas behavior, but overall adequate.

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 has 0% description coverage (only titles). The docstring clarifies each parameter (e.g., 'New left edge for the region' for dest_x), adding meaning beyond the schema. However, lacks ranges, defaults, or format specifics.

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 'Cut a rectangular region of pixels and paste it at a new position,' which is a specific verb-resource pair. It distinguishes from sibling tools like copy_region (copy without cutting) and 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 provides spatial behavior (sprite-global coordinates, transparent source area, out-of-bounds discard) but does not explicitly guide when to use move vs. alternatives like copy or cut. No direct sibling comparison.

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