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

The description discloses that the tool searches an archive and generates creative text (one-liner, short story, tweet). It adds value beyond the readOnlyHint annotation by specifying the outputs and their purpose. No destructive behavior is implied, and the description does not contradict 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 concise at three sentences, each serving a distinct purpose: stating the core functionality, detailing parameters with an example, and listing outputs and use cases. It is front-loaded with the main action and contains no redundant or extraneous information.

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 tool's moderate complexity (3 parameters, 1 required, output schema present), the description sufficiently covers what the tool does and what it returns. It explains the creative output types and use cases. While it could mention potential limitations or required access to the archive, it is largely 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?

Although the input schema already describes all three parameters with 100% coverage, the description adds contextual meaning by providing an example ('love + red returns...') and explaining how each parameter is used in the tool's logic. This helps agents understand the interplay between parameters 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 clearly states the tool's purpose: 'Find the most surprising archive colour for a concept and generate a memorable one-liner subverting the obvious expectation.' It specifies the verb 'find' and 'generate', the resource 'archive colour' and 'one-liner', and distinguishes itself from siblings by focusing on creative contradiction rather than basic color lookup or palette generation.

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 provides explicit when-to-use guidance: 'Supply a concept (e.g. 'love', 'grief', 'luxury', 'power') and optionally the expected colour.' It includes an example and suggests use cases ('public-facing demos, content, and brand storytelling'). However, it does not explicitly state when not to use this tool or mention alternative tools for similar tasks.

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