replace_color

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

No annotations provided, so description carries full burden. It states that alpha is preserved and gives tolerance parameter. However, it does not disclose whether the operation is destructive (it modifies the file directly), if it creates undo points, or any authorization needs. Basic behavioral context is present but incomplete.

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 a single sentence for purpose followed by a clear argument list. No wasted words. Front-loaded with the main action.

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?

The tool has 6 parameters and no output schema. The description explains all parameters sufficiently. It does not describe the return value or side effects, but the operation is straightforward (replace color in a cel). Minor omission: no mention of whether the file is saved automatically.

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 has 0% description coverage, so description must compensate. It fully explains all 6 parameters, including types and examples (e.g., 'Hex color to replace, e.g. "#FF0000"', 'Per-channel tolerance 0-255 (default 0 = exact match)'). This adds significant meaning beyond 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 starts with a specific verb and resource: 'Replace one color with another in a cel, preserving alpha.' This clearly distinguishes it from siblings like 'erase_color' (which erases a color) and 'remap_colors_in_cel_range' (which operates on a range).

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?

No explicit guidance on when to use this tool versus alternatives. It does not mention use cases, prerequisites, or when not to use it (e.g., for erasing, use erase_color).

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