Combine local images into a layout

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

Goes meaningfully beyond the annotations: it states a new file is written, that re-encoding can change pixels, that source metadata is stripped, and gives hard size caps (8192 px/side, 32 MP). That is real context not present in readOnlyHint/destructiveHint. The one notable omission is whether an existing file at output_path is overwritten or refused.

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?

Four dense sentences, front-loaded with the core verb+resource and followed by constraints and caveats; almost every clause carries information. The phrase 'using the existing abox.tools engine' is the one bit of near-filler.

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 12-parameter mutation tool with no output schema and 8% schema coverage, the description supplies the essential behavioral envelope (limits, format outcomes, metadata loss, layout defaults). Overwrite semantics for output_path and the quality/background parameters are the remaining gaps an agent would want.

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 8%, so the description must compensate, and it largely does: it explains gap, padding, contain/cover, cell ratios, format choices, columns default for grid, and the 8192 px/32 MP resolution ceiling. It leaves quality and the width default (1600) and background color semantics unaddressed, which is why this is not a 5.

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?

Names a specific verb (Arrange) and resource (still JPEG/PNG/WebP images) plus the exact output modes (grid, horizontal/vertical strip), which cleanly separates it from siblings like abox_images_to_video or abox_image_stack. It never names a sibling to contrast against, so it stops just short of the top band.

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?

Usage is implied by the input constraints (2-32 still images, absolute local paths) and by the stated defaults (grid = two square columns, strips preserve ratios), which helps an agent pick options. There is no explicit statement of when to prefer this over abox_image_stack or abox_images_to_pdf, and no exclusion guidance beyond the implicit 'still images only'.

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