util_color_by_element

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

With no annotations, the description carries the full burden. It states the basic function but does not disclose important behavioral traits: what color scheme is used (e.g., CPK), whether it overrides existing colors, if it affects all atoms or just the selection, or whether it's idempotent. The parameter 'selection' is not mentioned, leaving its effect unclear.

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, concise sentence, which is appropriate for a simple tool. However, it sacrifices necessary detail for brevity. A slightly longer description with parameter explanation and behavioral notes would improve usability without becoming verbose.

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 simplicity (one optional parameter, no required parameters, output schema exists), the description is insufficiently complete. It omits explanation of the parameter, the color scheme used, and the nature of the output. The agent has too little context to use the tool effectively.

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?

The input schema has 0% description coverage, and the tool description does not explain any parameters. The only parameter 'selection' (default 'all') is not described, so the agent cannot infer its purpose or valid values. The description adds no value beyond the schema structure.

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 that it colors atoms by their element. It is specific about what the tool does, distinguishing it from generic coloring tools like 'color' or other util functions like 'util_rainbow'. However, it does not explicitly differentiate from similar tools like 'util_color_secondary' or 'util_chainbow'.

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 guidance is provided on when to use this tool versus alternatives. There is no mention of typical use cases, prerequisites, or when to prefer other coloring tools (e.g., 'color', 'spectrum', or other util_* functions). The agent receives no context for decision-making.

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