compare_frames

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

With no annotations provided, the description carries full burden and does well: it discloses that the sprite is flattened non-destructively and that pixel-by-pixel diffing is used. It also describes the return format (JSON with pixel counts and bounding box), offering transparency beyond just the operation.

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 concise and well-structured: a one-line purpose, a brief behavioral explanation, a bulleted parameter list, and a return description. Every part adds value without redundancy.

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 no output schema, the description adequately covers return values (changed pixel count, total pixels, percent changed, bounding box). It is complete enough for a comparison tool, though edge cases or error conditions are not mentioned.

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 has 0% parameter description coverage, so the description adds significant value by explaining each parameter: filename, frame_a, and frame_b, including that frame indices start at 1. This meaningfully supplements the schema.

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's purpose: comparing two frames and reporting differences. It provides a specific use case ('Use while animating to confirm a frame actually changed') which distinguishes it from sibling tools focused on creation, deletion, or modification.

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 explicitly mentions when to use the tool (during animation to check for changes), giving clear context. However, it does not mention when not to use it or suggest alternatives among the many sibling frame-related tools.

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