pack_sprite_sheet

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

With no annotations, the description carries full burden. It discloses key behavioral traits: writes to disk, no preview returned, variable sprite sizes with automatic cell sizing, and optional base64 return. However, it does not mention whether the document is modified or other side effects.

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?

Two concise sentences with no wasted words. The first sentence provides the core operation and order, the second adds crucial context about delivery nature and the lack of preview. Every sentence earns its place.

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 9 parameters with complex defaults and no output schema, the description adequately covers the overall behavior, output format, and key defaults. It could mention that sprites are frames from documents, but that is evident from the 'doc_id' and 'frame' fields in the schema. Missing explicit mention of row-major order impact on layout, but it's clear enough.

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 coverage is high (89%), so baseline is 3. The description adds value by explaining 'cell dimensions default to the largest sprite', 'transparent border', and 'transparent pixels between cells', which directly clarify parameters margin, spacing, cell_width, cell_height. This goes beyond schema descriptions.

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 specifies the action ('Pack document frames'), the output ('transparent PNG sprite sheet'), and the order ('row-major'). It also distinguishes itself by stating 'This is delivery output and returns no preview image,' differentiating from possible preview tools among siblings.

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 lacks explicit guidance on when to use this tool versus alternatives like 'export' or 'split_sprite_sheet'. It only implies final delivery by stating 'delivery output' and 'no preview', but does not provide when-not-to-use or name alternative tools.

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