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

Annotations provide readOnlyHint=true, so the safety profile is already known. The description adds meaningful behavioral context beyond that: the returned result already contains rendered downloads that must be surfaced, the internal analysis steps (LRV, contrast, neutrals), and a warning about archive anchors being mistaken for recommended colours. This exceeds what annotations alone convey.

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 three sentences and every sentence adds value: core purpose, result-handling instruction, and a conditional follow-up with a critical warning. It is front-loaded with the main function and uses the later sentences for workflow. Slightly dense with multiple directives, but nothing is filler.

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 tool with only two parameters, a rich output schema, and read-only annotations, the description is adequate. It explains what the tool produces, how to present the result, and how to proceed if the agent makes a selection. It doesn't cover the use_case parameter, but the schema already does, so the information is complete enough for correct invocation.

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 both parameters. The description references 'from a palette' and the analysis steps, but does not add detail about the use_case parameter or the exact format of palette hex values. Since the schema carries the load, the baseline 3 is appropriate.

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 opens with a specific verb and resource: 'Generate light-mode and dark-mode role maps from a palette.' It clearly distinguishes itself from sibling palette tools by naming the exact output (role maps for two modes) and the analytical steps (LRV, role assignment, contrast check, neutral flagging). The title and description align, leaving no ambiguity about what this tool does.

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 gives clear workflow guidance: show the included downloads to the customer, and explicitly names palette_finalize as the follow-up when the agent chooses a final palette from the evidence. It also provides a strong negative directive ('Never present the archive anchors...'). It stops short of explicitly contrasting this tool with other palette_generate or palette_analyse alternatives, so it's not a full 5.

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