Palette

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

With no annotations, the description carries the burden and does well: it discloses the return format (CSS custom properties) and a genuine caveat that generated colors may fail contrast checks. It stops short of saying whether output is deterministic or how properties are named, but for a pure derivation function that is a minor gap.

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 tight sentences: capability and scheme options first, return type and caveat second. Nothing is redundant and nothing needs re-reading.

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?

For a two-parameter, single-output helper with no output schema, the description covers inputs, output medium, and a safety caveat. Only the concrete shape/naming of the emitted CSS variables is unstated, a small omission given the tool's simplicity.

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 already 100%, so the baseline is 3. The description adds real meaning by glossing 'complete' as 'all three plus tint/shade', which the schema only marks as the default; the hex input format is left to the schema, which handles it adequately.

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 (derive) and resource (colors) from a hex input, and enumerates the four scheme modes including what 'complete' means. An agent can distinguish this from check_contrast or extract_design_tokens without opening the schema.

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?

The phrase 'check contrast before use' gives a useful downstream workflow hint pointing toward the check_contrast sibling, but there is no explicit statement of when to choose palette over extract_design_tokens for existing colors. Usage is implied rather than prescribed.

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