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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description usefully adds billing context (10 credits, Tier 1), which is genuinely beyond the structured fields, but says nothing about how seed affects reproducibility or whether question influences the draw.

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 layout sentence is front-loaded and the metadata tags are compact. Nothing is padded, though the single content sentence is arguably too thin given the parameter surface.

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?

An output schema exists so return values need no explanation, and annotations cover safety, but with 5 optional parameters at 40% coverage and no usage guidance, an agent still cannot tell what question/seed do or when this spread beats its siblings.

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 only 40%: fields and precision are documented in the schema, but seed, question, and allowReversed are undocumented there. The description adds no parameter meaning at all, so it fails to compensate for the coverage gap on a 5-parameter tool.

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 names a specific resource and its internal structure (Past/Present/Future three-card spread), so an agent knows exactly what gets produced. It does not, however, distinguish this spread from the many sibling draws (single, celtic cross, relationship, horseshoe) beyond the implicit card count.

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?

There is no when-to-use guidance, no stated prerequisites, and no mention of alternative spreads for other question types. The agent must infer from the name alone which draw to pick.

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