replace_color

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

With no annotations, the description carries the full burden, and it does disclose one genuinely useful trait: the operation happens in 'a single undo transaction', so the agent knows the whole replacement is atomic and reversible in one step. It says nothing about the returnPreview behavior, tolerance handling, or whether layerName/frameNumber restrict the affected region.

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?

A single tight sentence with the action front-loaded and no filler. It is dense but every clause carries information, so it is appropriately sized for the tool.

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?

This is a mutation tool with no annotations, no output schema, and four of six parameters undocumented, yet the description only covers the atomic-undo trait. An agent still lacks the meaning of tolerance, the scoping effect of layerName/frameNumber, and what returnPreview produces.

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 only 33%: only toColor and fromColor are documented, and the description merely restates them rather than adding meaning. The four undocumented parameters (layerName, tolerance, frameNumber, returnPreview) are unexplained anywhere, and the description does not compensate for that gap.

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?

States a specific verb and resource ('Replaces all occurrences of fromColor with toColor') plus the scope ('across the cel or sprite'), which is enough to distinguish it from siblings like flood_fill or set_pixel. It does not name a sibling explicitly, so it stops short of a 5.

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?

There is no guidance on when to use this versus alternatives such as flood_fill, set_pixels, or set_palette_color, nor any prerequisites or exclusions. Scope is implied by the phrase 'across the cel or sprite' but the agent must infer when a global color swap is the right call.

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