util_chainbow

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 safety profile is covered. The description adds no behavioral context of its own: nothing about scope of effect (whole scene vs. object), reversibility, or whether the gradient is per-chain or per-residue.

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?

One short sentence with the action front-loaded, which is the right size for a simple utility. The parenthetical pun is mildly redundant once the action is stated but costs almost nothing.

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 is simple (one optional parameter, output schema present), so the description does not need return-value detail. However, for a state-mutating coloring utility surrounded by many similar siblings, the absence of scope and differentiation information leaves a real gap.

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 'selection' parameter is documented with a default of 'all'. The description's phrase 'colors chains' loosely implies the target of the selection but adds no format or syntax detail beyond the schema, so the baseline 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?

States a specific verb and resource: recolors chains in a rainbow gradient, and the parenthetical decodes an otherwise opaque tool name. It does not differentiate from siblings such as util_rainbow, spectrum, or the util_cb* family, which arguably do related coloring tasks.

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 use this versus util_rainbow or spectrum, no prerequisites, and no mention of whether the recoloring persists or can be undone. The agent must infer everything from the name and the single optional parameter.

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