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

Although readOnlyHint is already set, the description adds substantial behavioral context: per-colour nearest-match results, palette-level deduplication, embedded rendered palette and downloadable formats, and a guardrail against presenting archive anchor colours as recommendations. This goes well beyond the annotation.

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 longer than average but every sentence carries operational value: purpose, output contents, placement in workflow, result handling, and downstream tool routing. It is front-loaded with the core purpose and avoids 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?

Given the tool's complexity, the description is complete: it covers when to use it, what it returns, what the result includes, how to behave with the result, and what to do next. The output schema covers return structure, so the description need not duplicate that.

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?

The input schema has 100% description coverage for all parameters, so the baseline is 3. The description adds minimal new parameter semantics; it only reinforces that alternatives appear 'when confidence is low', which the schema already states for n. It does not materially deepen understanding of the parameters.

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 states a precise verb and resource: 'Analyse a palette of hex colours against the Colour Memory archive.' It clarifies the tool's output ('nearest named archive entry... claim_strength... alternatives') and differentiates it clearly from sibling tools like palette_extract, palette_generate, and palette_finalize by naming the workflow context.

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?

Explicit usage guidance is provided: 'Use after extracting colours from a photo or generating a palette.' It also names the fallback alternative, palette_finalize, and specifies when to invoke it ('If you go on to choose a final palette OF YOUR OWN... call palette_finalize once'). This leaves little to inference.

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