util_cbaw

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

Annotations declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the agent already knows this mutates state but is repeatable and non-destructive. The description adds only the 'white carbons' outcome and says nothing about whether existing colours are overwritten, whether the change persists in the session, or how it interacts with a partial selection — meaningful gaps for a state-mutating colour tool.

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?

It is short and front-loaded, but the brevity comes from under-specification rather than disciplined editing — the parenthetical 'Color By Atom, White' merely restates the same information as the first clause, so the sentence does not fully earn its place.

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?

With one optional parameter and an output schema, the mechanical interface is covered, but the description is not complete enough for a colour-scheme tool in a dense sibling family: the agent still cannot distinguish this scheme from the other util_cb* tools or predict the visual effect beyond 'carbons white'.

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% and the single parameter already has the description 'What to recolour. Defaults to everything.', so the schema carries the parameter semantics. The description's 'by atom' phrasing does not add scope, syntax, or selection-expression detail beyond that baseline.

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 phrase 'Colors by atom, white carbons' does convey the action (recolor atoms) and the scheme outcome (carbons white). However, it is essentially an expansion of the tool name 'util_cbaw', and it gives no differentiation from the many sibling colouring utilities (util_cbam, util_cbay, util_cbas, util_cbab, util_cbao, util_cbap, util_cbak), so an agent cannot tell which scheme this is relative to the others.

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?

There is no guidance on when to choose this scheme over the other util_cb* variants or util_color_by_element / util_chainbow / util_rainbow. The agent must infer that 'w' means white carbons and guess at the distinguishing condition, which is exactly the decision the description should support.

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