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

Annotations already cover readOnlyHint, idempotentHint, and destructiveHint, so the description does not need to restate them. It adds meaningful context by citing the Machado 2009 matrices and clarifying the output's purpose (what the palette looks like to colorblind readers), which goes beyond the bare schema.

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?

The description is a single efficient sentence that front-loads the core behavior ('Show what each color looks like') and packs the mode list, algorithm provenance, and intended use case without waste.

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 only two parameters, full schema coverage, and safety-oriented annotations, the description plus schema gives an agent enough context to select and invoke the tool. The only minor gap is that the output shape is not described, but no output schema exists and the phrase 'show what each color looks like' makes the expected result reasonably inferable.

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%, so the schema already documents 'colors' as CSS-syntax strings and 'modes' with its enum values and default. The description names the vision modes in prose, which adds minor reinforcement but no new semantic detail beyond the schema.

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 uses a specific verb ('Show what each color looks like') and names the exact resource (palette colors) and the four vision modes, grounding the simulation in published Machado 2009 matrices. This clearly distinguishes it from the sibling tools audit_palette, build_ramp, and solve_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?

The description states the intended context explicitly: use it when an assistant needs to describe or render a palette as a colorblind reader sees it. It does not explicitly enumerate exclusions or alternatives, but the intended scenario is clear and the simulation purpose is distinguishable from the sibling tools.

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