util_cbak

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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, so the safety profile is known. The description adds no behavioral context, such as that it overwrites existing atom colors, whether the change is scoped to a selection, or that residue/cartoon-level colors are left untouched. Nothing contradicts the 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?

Extremely short and front-loaded, with zero padding. The parenthetical mnemonic expansion is the only marginal content, and the terseness is efficient rather than disorganized.

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 an output schema and a fully documented single parameter, so the basics are covered. However, for one of roughly ten near-identical color-by-atom variants, the description does not explain what distinguishes this scheme, making correct tool selection between siblings largely guesswork.

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%: the single 'selection' parameter already documents 'What to recolour. Defaults to everything.' The description contributes no extra meaning about selection syntax or scope beyond that.

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?

"Colors by atom, pink carbons" states an action and the specific outcome (pink carbons), and the parenthetical hints at the mnemonic 'CBy Atom pinK'. But it never says this recolors a molecular selection by atom type, so the agent must infer the domain from the name and sibling cluster rather than the text.

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 on when to use this versus the many color-scheme siblings (util_cbam, util_cbay, util_cbas, util_cbab, util_cbao, util_cbap, util_cbac, util_cbaw, util_cbag) or versus generic tools like color and spectrum. The only differentiator is the parenthetical 'pinK'.

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