Transform

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

Annotations already indicate the tool is not read-only and not destructive, so the description does not need to restate that. It adds useful behavioral context: arbitrary rotations can visually ruin pixel art, non-90° angles need allowLossy, and scaling is nearest-neighbour/integer-only. This goes beyond the structured annotations and helps the agent choose safe settings.

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 sentences carry the behavior, the op list, and the key constraints without wasted words. The core action is front-loaded, and the caveats follow naturally. The em-dash and short clauses keep it scannable.

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 13-parameter tool with six ops, the definition could explain outline and crop_to_content more explicitly, but the schema covers most parameter meanings and an output schema exists. The description properly highlights the only genuinely dangerous behaviors (lossy rotation and scaling). The remaining gaps like thickness are minor and inferable from op name plus schema 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?

The schema already describes most parameters, including axis, angle, color, scope, factor, and allowLossy. The description adds conceptual rationale for rotation and scale constraints, but does not explain dx/dy semantics, thickness, frame, layer, or sprite. With 69% schema coverage, the description only partially compensates for the undocumented parameters.

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 opens with a specific verb phrase ('Move, flip, rotate or scale pixels') and enumerates all six operations by name. It names the resource ('pixels') and the operation set precisely, which clearly separates it from siblings like draw or recolor. Even without mentioning sibling tools, an agent can identify this as the geometric-transform tool.

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?

It gives implicit usage guidance by listing operations and warning that non-90 rotation and non-integer scale require allowLossy. However, it never says when to prefer an alternative tool or when not to use this one. The limits it mentions are parameter-level constraints, not cross-tool routing guidance.

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