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

Beyond the readOnlyHint annotation, the description discloses that the result already includes rendered palette downloads and instructs the agent to show them to the customer. It also warns against presenting archive anchors as recommendations and defines the exact next step if the agent chooses its own final palette, which is valuable behavioral context.

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 compact and front-loaded: the first sentence states the core function, the second highlights value, and the third provides necessary behavioral guardrails. Every sentence contributes something, though the wording could be tightened slightly without losing meaning.

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 single-parameter read-only tool with an output schema, the description covers the main return contents, how to present them, and the follow-up action when relevant. It does not describe edge cases or limits, but the combination of schema, annotations, and description is sufficient for correct invocation and use.

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% for the single parameter, so the schema already fully explains 'name'. The description adds little beyond the schema's own 'Named archive colour e.g. Bourton Honey' example; it reinforces that the value should be an archive colour name but does not introduce new semantic meaning.

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 ('return') and identifies the exact resource: historical variants, lighter/darker versions, archive matches, and cultural siblings for a named archive colour. It also sets this tool apart from nearby tools by emphasizing the 'exploring around a colour' use case and by explicitly naming palette_finalize as the follow-up for a different action.

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 clearly frames when the tool is useful ('Essential for designers exploring around a colour') and gives an explicit routing instruction to palette_finalize if the agent forms its own final palette. It does not exhaustively list when not to use it relative to every sibling, but the context and alternative are concrete enough.

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