lookup_color

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

With no annotations, the description carries the full burden of behavioral disclosure. It explains that queries can be numeric codes, direct colours, or partial names, and that matches return code, name, RGB, edge colour, alpha, and finish. It also explicitly states that unknown codes return no matches, which sets expectations for empty results.

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 compact and front-loaded, starting with the core purpose and then detailing query syntax and return fields. Every sentence adds useful information; there is no filler.

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 simple one-parameter lookup tool with an output schema available, the description fully covers what the agent needs: input format, matching semantics, output fields, and empty-result behavior. Nothing important is missing.

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 0%, so the description must compensate, and it does. It gives concrete examples of valid query forms ('4', '0x2FF8800', 'dark blue', 'Trans_Red') and describes the matching behavior, making the single string parameter's semantics fully clear.

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 looks up LDraw colours from the library's LDConfig.ldr, with a specific verb and resource. It differentiates itself from sibling tools like search_parts and render_ldraw_file by focusing on colour metadata rather than geometry or rendering.

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 makes it obvious when to use the tool: whenever an LDraw colour code or colour name needs to be resolved. It does not explicitly mention alternatives or exclusions, but the scope is clear enough that an agent would not confuse it with the listed sibling tools.

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