nearest_colors

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

With no annotations, the description carries the full burden. It usefully discloses a behavioral default (effect and transparent finishes excluded unless opted in), but says nothing about ordering of results, whether the nearest match is first, how limit truncates, or what happens with an unmatched hex. That is real context, but well short of full behavioral disclosure for an unannotated 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?

Two sentences, zero padding, with the core action front-loaded and the default-behavior caveat immediately after. Every clause earns 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?

No output schema and no annotations, so the description should do more. It covers palette scoping and the effect/transparency default, but omits result ordering, the meaning of the top-N limit, and the shape of the returned matches — gaps an agent would notice when interpreting results.

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 only 25%, so the description must compensate. It does add meaning for includeEffects via the "excludes effect and transparent finishes by default" clause, and paletteId is documented in the schema, but hex and limit get no explanatory treatment — the description never says limit is a top-N cap or that hex must be a 6-digit #RRGGBB value, even though the schema pattern enforces the format.

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 resource ("Find the nearest approximate RGB screen colors") and scopes it to "one palette," which implicitly separates it from the sibling match_across_palettes. What's missing is an explicit naming of that sibling, so the differentiation must be inferred from the phrase "in one palette."

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?

Usage is only implied: the "one palette" phrasing and the default exclusion of effects hint at the single-palette matching case, but the description never says when to choose this over match_across_palettes, get_color, or search_colors. No prerequisites or when-not-to-use conditions are given.

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