util_cbao

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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the mutation/idempotency profile is covered structurally. The description adds the concrete visual outcome (orange carbons) but says nothing about whether the change touches only the current selection's atoms, all representations, or object-level colour settings, nor that it is not written back to the file.

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?

Two short fragments, front-loaded with the effect and then the expansion of the abbreviation. Nothing is wasted, though the parenthetical expansion largely repeats the first clause.

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?

An output schema exists and the single parameter is fully documented, so the definition is mechanically callable. The remaining gap is disambiguation from a large family of interchangeable colour-by-atom siblings, which the description does not address.

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 description coverage is 100% and the single parameter already carries 'What to recolour. Defaults to everything.' The description adds no syntax, selection-expression format, or default behaviour beyond what the schema states, so the baseline of 3 applies.

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 names a specific verb and effect ('Colors by atom, orange carbons') and expands the cryptic abbreviation 'cbao' into 'Color By Atom, Orange', so an agent can infer the operation. It does not, however, distinguish this from the many near-identical siblings (util_cbam, util_cbay, util_cbas, util_cbaw, util_color_by_element), which is exactly where differentiation is needed.

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 when-to-use guidance, no precondition, and no mention of alternatives such as util_color_by_element or the other cb* variants. With roughly a dozen sibling colouring tools, omitting any selection rule leaves the agent to guess from the abbreviation alone.

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