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

No annotations are present, so the description carries the burden. It does disclose the core output behavior (four hues 90 degrees apart), which is the key trait for this tool, but it says nothing about determinism or edge handling for out-of-range hues.

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 sentences, front-loaded with the operation and its definition, followed by the input constraint and return shape. No 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 simple stateless harmony calculator with no output schema and no annotations, the description covers input range and output shape adequately. Only minor gaps (out-of-range behavior) remain.

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 single parameter's schema description is only "Hue to process", while the description adds the meaningful 0-360 range constraint. This is real added value beyond the schema, though it does not reconcile the schema's string type.

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 gives a specific verb ("Generate") and resource ("tetradic (4-color) color harmony from a hue"), and defines what tetradic means. It implicitly differentiates from sibling harmony tools like x402-triadic/complementary by naming the harmony type, though it does not explicitly call them out.

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?

It tells the agent what input to supply ("Provide hue (0-360)"), which is basic usage guidance, but it never states when to prefer this harmony over the related triadic/complementary/split-complementary siblings, nor any exclusions.

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