Compare Two Colours — Perceptual and Cultural

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

Annotations declare readOnlyHint=true, and the description adds detailed behavioral context about what is returned (quantified differences, cultural context, comparisons). No contradictions; description enriches understanding of tool behavior beyond annotations.

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 efficient but the first sentence is dense with information; could be slightly more structured. However, key points are front-loaded and no words are wasted.

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 the complexity of the tool (perceptual and cultural comparison), the description covers inputs, outputs, usage guidance, and behavioral caveats. An output schema exists, so return values are further documented. The description is fully complete for an agent to select and invoke correctly.

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 100% with descriptions for both hex parameters. The tool description adds no additional meaning beyond the schema, so baseline score of 3 is appropriate.

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 uses specific verbs ('deep perceptual and semantic comparison') and resource ('any two hex values'), and lists concrete outputs (LRV, chroma, hue angle, etc.). It clearly distinguishes from sibling tools by stating it is not a harmony tool but a decision and reasoning 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?

Explicitly states when to use ('choosing between two colours or explaining why one works better') and when not to ('Not a harmony tool'), providing clear context for selection among sibling tools.

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